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I want to return in Seconds, Minuites, Hours, Days, Months et Years from Datetime created.
I wrote this snippet of code
public static string ReturnCreatedSince(DateTime createdOn)
{
//Get current datetime
var today = DateTime.Now;
// Get days in current month
var daysInMonth = DateTime.DaysInMonth(today.Year, today.Month);
double seconds = 60;
double minutes = seconds * 60;
double hours = minutes * 60;
double days = hours * 24;
//double weeks = days * 7;
double months = days * daysInMonth;
double years = months * 12;
//Convert created datetime to seconds
var datetimeInSeconds = (today - createdOn).TotalSeconds;
var createdSince = string.Empty;
if (datetimeInSeconds <= seconds) //seconds between 1 to 60
{
return TimeSpan.FromSeconds(datetimeInSeconds).Seconds.ToString() + " sec";
}
else if (datetimeInSeconds <= minutes)// Minuites between 1 to 60
{
return TimeSpan.FromSeconds(datetimeInSeconds).Minutes.ToString() + " mins";
}
else if (datetimeInSeconds <= hours)// Hours between 1 to 24
{
return TimeSpan.FromSeconds(datetimeInSeconds).Hours.ToString() + " hrs";
}
else if (datetimeInSeconds <= days)// Days between 1 to 24
{
return TimeSpan.FromSeconds(datetimeInSeconds).Days.ToString() + " jrs";
}
else if (datetimeInSeconds <= months)// Months between 1 to 24
{
return (datetimeInSeconds / months).ToString() + " m";
}
else if (datetimeInSeconds <= years)// Years between 1 to 12
{
return (datetimeInSeconds / years).ToString() + " yrs";
}
else
{
return createdOn.ToShortDateString();
}
}
I tested the code with the following values
Edited
For a given datetime
if the number of second is less than 60 then it should return the value in second.
if the number of second is less greater 60 and less than (60 * 60) secs then it should return the value in mins , the same apply for hours, days months and years
Now i have this date "createdOn": "2017-10-16T14:41:16.557" and return 41 days instead of 1 month expected.
how can i fix it
#Tarik solution for months will get you the total number of months between the startDate and endDate.
To get the last remaining months, include this while loop statement.
DateTime startDate = new DateTime(2003, 1, 1);
DateTime endDate = new DateTime(2007, 12, 1);
int nbYears = endDate.Year - startDate.Year;
int nbMonths = ((endDate.Year - startDate.Year) * 12) + endDate.Month - startDate.Month;
while (nbMonths > 12)
{
nbMonths = nbMonths % 12;
}
Console.WriteLine($"{nbYears} year(s) and {nbMonths} month(s)");
Without the while loop, it prints: 4 year(s) and 59 month(s)
With the while loop, it prints: 4 year(s) and 11 month(s)
It might be easier to use embedded methods :
DateTime startDate = new DateTime(1970, 01, 01);
DateTime endDate = DateTime.Now.ToUniversalTime();
TimeSpan diff = (endDate - startDate);
Console.WriteLine("Number of seconds:" + diff.TotalSeconds);
Console.WriteLine("Number of minutes:" + diff.TotalDays);
Console.WriteLine("Number of hours:" + diff.TotalHours );
Console.WriteLine("Number of days:" + diff.TotalDays);
//months
int nbMonths = ((endDate.Year - startDate.Year) * 12) + endDate.Month - startDate.Month;
Console.WriteLine("Number of months:" + nbMonths);
//years
int nbYears = endDate.Year - startDate.Year;
Console.WriteLine("Number of years:" + nbYears);
Console.ReadKey();
How to calculate the difference in months between two dates in C#?
Is there is equivalent of VB's DateDiff() method in C#. I need to find difference in months between two dates that are years apart. The documentation says that I can use TimeSpan like:
TimeSpan ts = date1 - date2;
but this gives me data in Days. I don't want to divide this number by 30 because not every month is 30 days and since the two operand values are quite apart from each other, I am afraid dividing by 30 might give me a wrong value.
Any suggestions?
Assuming the day of the month is irrelevant (i.e. the diff between 2011.1.1 and 2010.12.31 is 1), with date1 > date2 giving a positive value and date2 > date1 a negative value
((date1.Year - date2.Year) * 12) + date1.Month - date2.Month
Or, assuming you want an approximate number of 'average months' between the two dates, the following should work for all but very huge date differences.
date1.Subtract(date2).Days / (365.25 / 12)
Note, if you were to use the latter solution then your unit tests should state the widest date range which your application is designed to work with and validate the results of the calculation accordingly.
Update (with thanks to Gary)
If using the 'average months' method, a slightly more accurate number to use for the 'average number of days per year' is 365.2425.
Here is a comprehensive solution to return a DateTimeSpan, similar to a TimeSpan, except that it includes all the date components in addition to the time components.
Usage:
void Main()
{
DateTime compareTo = DateTime.Parse("8/13/2010 8:33:21 AM");
DateTime now = DateTime.Parse("2/9/2012 10:10:11 AM");
var dateSpan = DateTimeSpan.CompareDates(compareTo, now);
Console.WriteLine("Years: " + dateSpan.Years);
Console.WriteLine("Months: " + dateSpan.Months);
Console.WriteLine("Days: " + dateSpan.Days);
Console.WriteLine("Hours: " + dateSpan.Hours);
Console.WriteLine("Minutes: " + dateSpan.Minutes);
Console.WriteLine("Seconds: " + dateSpan.Seconds);
Console.WriteLine("Milliseconds: " + dateSpan.Milliseconds);
}
Outputs:
Years: 1
Months: 5
Days: 27
Hours: 1
Minutes: 36
Seconds: 50
Milliseconds: 0
For convenience, I've lumped the logic into the DateTimeSpan struct, but you may move the method CompareDates wherever you see fit. Also note, it doesn't matter which date comes before the other.
public struct DateTimeSpan
{
public int Years { get; }
public int Months { get; }
public int Days { get; }
public int Hours { get; }
public int Minutes { get; }
public int Seconds { get; }
public int Milliseconds { get; }
public DateTimeSpan(int years, int months, int days, int hours, int minutes, int seconds, int milliseconds)
{
Years = years;
Months = months;
Days = days;
Hours = hours;
Minutes = minutes;
Seconds = seconds;
Milliseconds = milliseconds;
}
enum Phase { Years, Months, Days, Done }
public static DateTimeSpan CompareDates(DateTime date1, DateTime date2)
{
if (date2 < date1)
{
var sub = date1;
date1 = date2;
date2 = sub;
}
DateTime current = date1;
int years = 0;
int months = 0;
int days = 0;
Phase phase = Phase.Years;
DateTimeSpan span = new DateTimeSpan();
int officialDay = current.Day;
while (phase != Phase.Done)
{
switch (phase)
{
case Phase.Years:
if (current.AddYears(years + 1) > date2)
{
phase = Phase.Months;
current = current.AddYears(years);
}
else
{
years++;
}
break;
case Phase.Months:
if (current.AddMonths(months + 1) > date2)
{
phase = Phase.Days;
current = current.AddMonths(months);
if (current.Day < officialDay && officialDay <= DateTime.DaysInMonth(current.Year, current.Month))
current = current.AddDays(officialDay - current.Day);
}
else
{
months++;
}
break;
case Phase.Days:
if (current.AddDays(days + 1) > date2)
{
current = current.AddDays(days);
var timespan = date2 - current;
span = new DateTimeSpan(years, months, days, timespan.Hours, timespan.Minutes, timespan.Seconds, timespan.Milliseconds);
phase = Phase.Done;
}
else
{
days++;
}
break;
}
}
return span;
}
}
You could do
if ( date1.AddMonths(x) > date2 )
If you want the exact number of full months, always positive (2000-01-15, 2000-02-14 returns 0), considering a full month is when you reach the same day the next month (something like the age calculation)
public static int GetMonthsBetween(DateTime from, DateTime to)
{
if (from > to) return GetMonthsBetween(to, from);
var monthDiff = Math.Abs((to.Year * 12 + (to.Month - 1)) - (from.Year * 12 + (from.Month - 1)));
if (from.AddMonths(monthDiff) > to || to.Day < from.Day)
{
return monthDiff - 1;
}
else
{
return monthDiff;
}
}
Edit reason: the old code was not correct in some cases like :
new { From = new DateTime(1900, 8, 31), To = new DateTime(1901, 8, 30), Result = 11 },
Test cases I used to test the function:
var tests = new[]
{
new { From = new DateTime(1900, 1, 1), To = new DateTime(1900, 1, 1), Result = 0 },
new { From = new DateTime(1900, 1, 1), To = new DateTime(1900, 1, 2), Result = 0 },
new { From = new DateTime(1900, 1, 2), To = new DateTime(1900, 1, 1), Result = 0 },
new { From = new DateTime(1900, 1, 1), To = new DateTime(1900, 2, 1), Result = 1 },
new { From = new DateTime(1900, 2, 1), To = new DateTime(1900, 1, 1), Result = 1 },
new { From = new DateTime(1900, 1, 31), To = new DateTime(1900, 2, 1), Result = 0 },
new { From = new DateTime(1900, 8, 31), To = new DateTime(1900, 9, 30), Result = 0 },
new { From = new DateTime(1900, 8, 31), To = new DateTime(1900, 10, 1), Result = 1 },
new { From = new DateTime(1900, 1, 1), To = new DateTime(1901, 1, 1), Result = 12 },
new { From = new DateTime(1900, 1, 1), To = new DateTime(1911, 1, 1), Result = 132 },
new { From = new DateTime(1900, 8, 31), To = new DateTime(1901, 8, 30), Result = 11 },
};
I checked the usage of this method in VB.NET via MSDN and it seems that it has a lot of usages. There is no such a built-in method in C#. (Even it's not a good idea) you can call VB's in C#.
Add Microsoft.VisualBasic.dll to
your project as a reference
use
Microsoft.VisualBasic.DateAndTime.DateDiff
in your code
Use Noda Time:
LocalDate start = new LocalDate(2013, 1, 5);
LocalDate end = new LocalDate(2014, 6, 1);
Period period = Period.Between(start, end, PeriodUnits.Months);
Console.WriteLine(period.Months); // 16
(example source)
To get difference in months (both start and end inclusive), irrespective of dates:
DateTime start = new DateTime(2013, 1, 1);
DateTime end = new DateTime(2014, 2, 1);
var diffMonths = (end.Month + end.Year * 12) - (start.Month + start.Year * 12);
I just needed something simple to cater for e.g. employment dates where only the month/year is entered, so wanted distinct years and months worked in. This is what I use, here for usefullness only
public static YearsMonths YearMonthDiff(DateTime startDate, DateTime endDate) {
int monthDiff = ((endDate.Year * 12) + endDate.Month) - ((startDate.Year * 12) + startDate.Month) + 1;
int years = (int)Math.Floor((decimal) (monthDiff / 12));
int months = monthDiff % 12;
return new YearsMonths {
TotalMonths = monthDiff,
Years = years,
Months = months
};
}
.NET Fiddle
You can use Noda Time https://nodatime.org/
LocalDate start = new LocalDate(2010, 1, 5);
LocalDate end = new LocalDate(2012, 6, 1);
Period period = Period.Between(start, end, PeriodUnits.Months);
Console.WriteLine(period.Months);
You can use the DateDiff class of the Time Period Library for .NET:
// ----------------------------------------------------------------------
public void DateDiffSample()
{
DateTime date1 = new DateTime( 2009, 11, 8, 7, 13, 59 );
DateTime date2 = new DateTime( 2011, 3, 20, 19, 55, 28 );
DateDiff dateDiff = new DateDiff( date1, date2 );
// differences
Console.WriteLine( "DateDiff.Months: {0}", dateDiff.Months );
// > DateDiff.Months: 16
// elapsed
Console.WriteLine( "DateDiff.ElapsedMonths: {0}", dateDiff.ElapsedMonths );
// > DateDiff.ElapsedMonths: 4
// description
Console.WriteLine( "DateDiff.GetDescription(6): {0}", dateDiff.GetDescription( 6 ) );
// > DateDiff.GetDescription(6): 1 Year 4 Months 12 Days 12 Hours 41 Mins 29 Secs
} // DateDiffSample
Here is my contribution to get difference in Months that I've found to be accurate:
namespace System
{
public static class DateTimeExtensions
{
public static Int32 DiffMonths( this DateTime start, DateTime end )
{
Int32 months = 0;
DateTime tmp = start;
while ( tmp < end )
{
months++;
tmp = tmp.AddMonths( 1 );
}
return months;
}
}
}
Usage:
Int32 months = DateTime.Now.DiffMonths( DateTime.Now.AddYears( 5 ) );
You can create another method called DiffYears and apply exactly the same logic as above and AddYears instead of AddMonths in the while loop.
This worked for what I needed it for. The day of month didn't matter in my case because it always happens to be the last day of the month.
public static int MonthDiff(DateTime d1, DateTime d2){
int retVal = 0;
if (d1.Month<d2.Month)
{
retVal = (d1.Month + 12) - d2.Month;
retVal += ((d1.Year - 1) - d2.Year)*12;
}
else
{
retVal = d1.Month - d2.Month;
retVal += (d1.Year - d2.Year)*12;
}
//// Calculate the number of years represented and multiply by 12
//// Substract the month number from the total
//// Substract the difference of the second month and 12 from the total
//retVal = (d1.Year - d2.Year) * 12;
//retVal = retVal - d1.Month;
//retVal = retVal - (12 - d2.Month);
return retVal;
}
There's 3 cases: same year, previous year and other years.
If the day of the month does not matter...
public int GetTotalNumberOfMonths(DateTime start, DateTime end)
{
// work with dates in the right order
if (start > end)
{
var swapper = start;
start = end;
end = swapper;
}
switch (end.Year - start.Year)
{
case 0: // Same year
return end.Month - start.Month;
case 1: // last year
return (12 - start.Month) + end.Month;
default:
return 12 * (3 - (end.Year - start.Year)) + (12 - start.Month) + end.Month;
}
}
The most precise way is this that return difference in months by fraction :
private double ReturnDiffereceBetweenTwoDatesInMonths(DateTime startDateTime, DateTime endDateTime)
{
double result = 0;
double days = 0;
DateTime currentDateTime = startDateTime;
while (endDateTime > currentDateTime.AddMonths(1))
{
result ++;
currentDateTime = currentDateTime.AddMonths(1);
}
if (endDateTime > currentDateTime)
{
days = endDateTime.Subtract(currentDateTime).TotalDays;
}
return result + days/endDateTime.GetMonthDays;
}
My understanding of the total months difference between 2 dates has an integral and a fractional part (the date matters).
The integral part is the full months difference.
The fractional part, for me, is the difference of the % of the day (to the full days of month) between the starting and ending months.
public static class DateTimeExtensions
{
public static double TotalMonthsDifference(this DateTime from, DateTime to)
{
//Compute full months difference between dates
var fullMonthsDiff = (to.Year - from.Year)*12 + to.Month - from.Month;
//Compute difference between the % of day to full days of each month
var fractionMonthsDiff = ((double)(to.Day-1) / (DateTime.DaysInMonth(to.Year, to.Month)-1)) -
((double)(from.Day-1)/ (DateTime.DaysInMonth(from.Year, from.Month)-1));
return fullMonthsDiff + fractionMonthsDiff;
}
}
With this extension, those are the results:
2/29/2000 TotalMonthsDifference 2/28/2001 => 12
2/28/2000 TotalMonthsDifference 2/28/2001 => 12.035714285714286
01/01/2000 TotalMonthsDifference 01/16/2000 => 0.5
01/31/2000 TotalMonthsDifference 01/01/2000 => -1.0
01/31/2000 TotalMonthsDifference 02/29/2000 => 1.0
01/31/2000 TotalMonthsDifference 02/28/2000 => 0.9642857142857143
01/31/2001 TotalMonthsDifference 02/28/2001 => 1.0
Here is a simple solution that works at least for me. It's probably not the fastest though because it uses the cool DateTime's AddMonth feature in a loop:
public static int GetMonthsDiff(DateTime start, DateTime end)
{
if (start > end)
return GetMonthsDiff(end, start);
int months = 0;
do
{
start = start.AddMonths(1);
if (start > end)
return months;
months++;
}
while (true);
}
This simple static function calculates the fraction of months between two Datetimes, e.g.
1.1. to 31.1. = 1.0
1.4. to 15.4. = 0.5
16.4. to 30.4. = 0.5
1.3. to 1.4. = 1 + 1/30
The function assumes that the first date is smaller than the second date. To deal with negative time intervals one can modify the function easily by introducing a sign and a variable swap at the beginning.
public static double GetDeltaMonths(DateTime t0, DateTime t1)
{
DateTime t = t0;
double months = 0;
while(t<=t1)
{
int daysInMonth = DateTime.DaysInMonth(t.Year, t.Month);
DateTime endOfMonth = new DateTime(t.Year, t.Month, daysInMonth);
int cutDay = endOfMonth <= t1 ? daysInMonth : t1.Day;
months += (cutDay - t.Day + 1) / (double) daysInMonth;
t = new DateTime(t.Year, t.Month, 1).AddMonths(1);
}
return Math.Round(months,2);
}
one line solution
For first, check if both dates are in the current year, if not get months of whole years and then add months from the start and end year.
DateTime dateFrom = new DateTime(2019, 2, 1);
DateTime dateTo = new DateTime(2021, 5, 25);
With the first month
var monthCount = dateFrom.Year != dateTo.Year ? ((dateTo.Year - dateFrom.Year - 1) * 12) + (13 - dateFrom.Month + dateTo.Month) : dateTo.Month - dateFrom.Month + 1;
result = 28
Without first month
monthCount = dateFrom.Year != dateTo.Year ? ((dateTo.Year - dateFrom.Year - 1) * 12) + (12 - dateFrom.Month + dateTo.Month) : dateTo.Month - dateFrom.Month;
result = 27
Public Class ClassDateOperation
Private prop_DifferenceInDay As Integer
Private prop_DifferenceInMonth As Integer
Private prop_DifferenceInYear As Integer
Public Function DayMonthYearFromTwoDate(ByVal DateStart As Date, ByVal DateEnd As Date) As ClassDateOperation
Dim differenceInDay As Integer
Dim differenceInMonth As Integer
Dim differenceInYear As Integer
Dim myDate As Date
DateEnd = DateEnd.AddDays(1)
differenceInYear = DateEnd.Year - DateStart.Year
If DateStart.Month <= DateEnd.Month Then
differenceInMonth = DateEnd.Month - DateStart.Month
Else
differenceInYear -= 1
differenceInMonth = (12 - DateStart.Month) + DateEnd.Month
End If
If DateStart.Day <= DateEnd.Day Then
differenceInDay = DateEnd.Day - DateStart.Day
Else
myDate = CDate("01/" & DateStart.AddMonths(1).Month & "/" & DateStart.Year).AddDays(-1)
If differenceInMonth <> 0 Then
differenceInMonth -= 1
Else
differenceInMonth = 11
differenceInYear -= 1
End If
differenceInDay = myDate.Day - DateStart.Day + DateEnd.Day
End If
prop_DifferenceInDay = differenceInDay
prop_DifferenceInMonth = differenceInMonth
prop_DifferenceInYear = differenceInYear
Return Me
End Function
Public ReadOnly Property DifferenceInDay() As Integer
Get
Return prop_DifferenceInDay
End Get
End Property
Public ReadOnly Property DifferenceInMonth As Integer
Get
Return prop_DifferenceInMonth
End Get
End Property
Public ReadOnly Property DifferenceInYear As Integer
Get
Return prop_DifferenceInYear
End Get
End Property
End Class
This is from my own library, will return the difference of months between two dates.
public static int MonthDiff(DateTime d1, DateTime d2)
{
int retVal = 0;
// Calculate the number of years represented and multiply by 12
// Substract the month number from the total
// Substract the difference of the second month and 12 from the total
retVal = (d1.Year - d2.Year) * 12;
retVal = retVal - d1.Month;
retVal = retVal - (12 - d2.Month);
return retVal;
}
You can have a function something like this.
For Example, from 2012/12/27 to 2012/12/29 becomes 3 days. Likewise, from 2012/12/15 to 2013/01/15 becomes 2 months, because up to 2013/01/14 it's 1 month. from 15th it's 2nd month started.
You can remove the "=" in the second if condition, if you do not want to include both days in the calculation. i.e, from 2012/12/15 to 2013/01/15 is 1 month.
public int GetMonths(DateTime startDate, DateTime endDate)
{
if (startDate > endDate)
{
throw new Exception("Start Date is greater than the End Date");
}
int months = ((endDate.Year * 12) + endDate.Month) - ((startDate.Year * 12) + startDate.Month);
if (endDate.Day >= startDate.Day)
{
months++;
}
return months;
}
you can use the following extension:
Code
public static class Ext
{
#region Public Methods
public static int GetAge(this DateTime #this)
{
var today = DateTime.Today;
return ((((today.Year - #this.Year) * 100) + (today.Month - #this.Month)) * 100 + today.Day - #this.Day) / 10000;
}
public static int DiffMonths(this DateTime #from, DateTime #to)
{
return (((((#to.Year - #from.Year) * 12) + (#to.Month - #from.Month)) * 100 + #to.Day - #from.Day) / 100);
}
public static int DiffYears(this DateTime #from, DateTime #to)
{
return ((((#to.Year - #from.Year) * 100) + (#to.Month - #from.Month)) * 100 + #to.Day - #from.Day) / 10000;
}
#endregion Public Methods
}
Implementation !
int Age;
int years;
int Months;
//Replace your own date
var d1 = new DateTime(2000, 10, 22);
var d2 = new DateTime(2003, 10, 20);
//Age
Age = d1.GetAge();
Age = d2.GetAge();
//positive
years = d1.DiffYears(d2);
Months = d1.DiffMonths(d2);
//negative
years = d2.DiffYears(d1);
Months = d2.DiffMonths(d1);
//Or
Months = Ext.DiffMonths(d1, d2);
years = Ext.DiffYears(d1, d2);
Here's a much more concise solution using VB.Net DateDiff for Year, Month, Day only. You can load the DateDiff library in C# as well.
date1 must be <= date2
VB.NET
Dim date1 = Now.AddDays(-2000)
Dim date2 = Now
Dim diffYears = DateDiff(DateInterval.Year, date1, date2) - If(date1.DayOfYear > date2.DayOfYear, 1, 0)
Dim diffMonths = DateDiff(DateInterval.Month, date1, date2) - diffYears * 12 - If(date1.Day > date2.Day, 1, 0)
Dim diffDays = If(date2.Day >= date1.Day, date2.Day - date1.Day, date2.Day + (Date.DaysInMonth(date1.Year, date1.Month) - date1.Day))
C#
DateTime date1 = Now.AddDays(-2000);
DateTime date2 = Now;
int diffYears = DateDiff(DateInterval.Year, date1, date2) - date1.DayOfYear > date2.DayOfYear ? 1 : 0;
int diffMonths = DateDiff(DateInterval.Month, date1, date2) - diffYears * 12 - date1.Day > date2.Day ? 1 : 0;
int diffDays = date2.Day >= date1.Day ? date2.Day - date1.Day : date2.Day + (System.DateTime.DaysInMonth(date1.Year, date1.Month) - date1.Day);
This is in response to Kirk Woll's answer. I don't have enough reputation points to reply to a comment yet...
I liked Kirk's solution and was going to shamelessly rip it off and use it in my code, but when I looked through it I realized it's way too complicated. Unnecessary switching and looping, and a public constructor that is pointless to use.
Here's my rewrite:
public class DateTimeSpan {
private DateTime _date1;
private DateTime _date2;
private int _years;
private int _months;
private int _days;
private int _hours;
private int _minutes;
private int _seconds;
private int _milliseconds;
public int Years { get { return _years; } }
public int Months { get { return _months; } }
public int Days { get { return _days; } }
public int Hours { get { return _hours; } }
public int Minutes { get { return _minutes; } }
public int Seconds { get { return _seconds; } }
public int Milliseconds { get { return _milliseconds; } }
public DateTimeSpan(DateTime date1, DateTime date2) {
_date1 = (date1 > date2) ? date1 : date2;
_date2 = (date2 < date1) ? date2 : date1;
_years = _date1.Year - _date2.Year;
_months = (_years * 12) + _date1.Month - _date2.Month;
TimeSpan t = (_date2 - _date1);
_days = t.Days;
_hours = t.Hours;
_minutes = t.Minutes;
_seconds = t.Seconds;
_milliseconds = t.Milliseconds;
}
public static DateTimeSpan CompareDates(DateTime date1, DateTime date2) {
return new DateTimeSpan(date1, date2);
}
}
Usage1, pretty much the same:
void Main()
{
DateTime compareTo = DateTime.Parse("8/13/2010 8:33:21 AM");
DateTime now = DateTime.Parse("2/9/2012 10:10:11 AM");
var dateSpan = new DateTimeSpan(compareTo, now);
Console.WriteLine("Years: " + dateSpan.Years);
Console.WriteLine("Months: " + dateSpan.Months);
Console.WriteLine("Days: " + dateSpan.Days);
Console.WriteLine("Hours: " + dateSpan.Hours);
Console.WriteLine("Minutes: " + dateSpan.Minutes);
Console.WriteLine("Seconds: " + dateSpan.Seconds);
Console.WriteLine("Milliseconds: " + dateSpan.Milliseconds);
}
Usage2, similar:
void Main()
{
DateTime compareTo = DateTime.Parse("8/13/2010 8:33:21 AM");
DateTime now = DateTime.Parse("2/9/2012 10:10:11 AM");
Console.WriteLine("Years: " + DateTimeSpan.CompareDates(compareTo, now).Years);
Console.WriteLine("Months: " + DateTimeSpan.CompareDates(compareTo, now).Months);
Console.WriteLine("Days: " + DateTimeSpan.CompareDates(compareTo, now).Days);
Console.WriteLine("Hours: " + DateTimeSpan.CompareDates(compareTo, now).Hours);
Console.WriteLine("Minutes: " + DateTimeSpan.CompareDates(compareTo, now).Minutes);
Console.WriteLine("Seconds: " + DateTimeSpan.CompareDates(compareTo, now).Seconds);
Console.WriteLine("Milliseconds: " + DateTimeSpan.CompareDates(compareTo, now).Milliseconds);
}
In my case it is required to calculate the complete month from the start date to the day prior to this day in the next month or from start to end of month.
Ex: from 1/1/2018 to 31/1/2018 is a complete month
Ex2: from 5/1/2018 to 4/2/2018 is a complete month
so based on this here is my solution:
public static DateTime GetMonthEnd(DateTime StartDate, int MonthsCount = 1)
{
return StartDate.AddMonths(MonthsCount).AddDays(-1);
}
public static Tuple<int, int> CalcPeriod(DateTime StartDate, DateTime EndDate)
{
int MonthsCount = 0;
Tuple<int, int> Period;
while (true)
{
if (GetMonthEnd(StartDate) > EndDate)
break;
else
{
MonthsCount += 1;
StartDate = StartDate.AddMonths(1);
}
}
int RemainingDays = (EndDate - StartDate).Days + 1;
Period = new Tuple<int, int>(MonthsCount, RemainingDays);
return Period;
}
Usage:
Tuple<int, int> Period = CalcPeriod(FromDate, ToDate);
Note: in my case it was required to calculate the remaining days after the complete months so if it's not your case you could ignore the days result or even you could change the method return from tuple to integer.
public static int PayableMonthsInDuration(DateTime StartDate, DateTime EndDate)
{
int sy = StartDate.Year; int sm = StartDate.Month; int count = 0;
do
{
count++;if ((sy == EndDate.Year) && (sm >= EndDate.Month)) { break; }
sm++;if (sm == 13) { sm = 1; sy++; }
} while ((EndDate.Year >= sy) || (EndDate.Month >= sm));
return (count);
}
This solution is for Rental/subscription calculation, where difference doesn't means to be subtraction, it's meant to be the span in within those two dates.
I wrote a function to accomplish this, because the others ways weren't working for me.
public string getEndDate (DateTime startDate,decimal monthCount)
{
int y = startDate.Year;
int m = startDate.Month;
for (decimal i = monthCount; i > 1; i--)
{
m++;
if (m == 12)
{ y++;
m = 1;
}
}
return string.Format("{0}-{1}-{2}", y.ToString(), m.ToString(), startDate.Day.ToString());
}
There are not a lot of clear answers on this because you are always assuming things.
This solution calculates between two dates the months between assuming you want to save the day of month for comparison, (meaning that the day of the month is considered in the calculation)
Example, if you have a date of 30 Jan 2012, 29 Feb 2012 will not be a month but 01 March 2013 will.
It's been tested pretty thoroughly, probably will clean it up later as we use it, but here:
private static int TotalMonthDifference(DateTime dtThis, DateTime dtOther)
{
int intReturn = 0;
bool sameMonth = false;
if (dtOther.Date < dtThis.Date) //used for an error catch in program, returns -1
intReturn--;
int dayOfMonth = dtThis.Day; //captures the month of day for when it adds a month and doesn't have that many days
int daysinMonth = 0; //used to caputre how many days are in the month
while (dtOther.Date > dtThis.Date) //while Other date is still under the other
{
dtThis = dtThis.AddMonths(1); //as we loop, we just keep adding a month for testing
daysinMonth = DateTime.DaysInMonth(dtThis.Year, dtThis.Month); //grabs the days in the current tested month
if (dtThis.Day != dayOfMonth) //Example 30 Jan 2013 will go to 28 Feb when a month is added, so when it goes to march it will be 28th and not 30th
{
if (daysinMonth < dayOfMonth) // uses day in month max if can't set back to day of month
dtThis.AddDays(daysinMonth - dtThis.Day);
else
dtThis.AddDays(dayOfMonth - dtThis.Day);
}
if (((dtOther.Year == dtThis.Year) && (dtOther.Month == dtThis.Month))) //If the loop puts it in the same month and year
{
if (dtOther.Day >= dayOfMonth) //check to see if it is the same day or later to add one to month
intReturn++;
sameMonth = true; //sets this to cancel out of the normal counting of month
}
if ((!sameMonth)&&(dtOther.Date > dtThis.Date))//so as long as it didn't reach the same month (or if i started in the same month, one month ahead, add a month)
intReturn++;
}
return intReturn; //return month
}
Based on the excellent DateTimeSpan work done above, I've normalized the code a bit; this seems to work pretty well:
public class DateTimeSpan
{
private DateTimeSpan() { }
private DateTimeSpan(int years, int months, int days, int hours, int minutes, int seconds, int milliseconds)
{
Years = years;
Months = months;
Days = days;
Hours = hours;
Minutes = minutes;
Seconds = seconds;
Milliseconds = milliseconds;
}
public int Years { get; private set; } = 0;
public int Months { get; private set; } = 0;
public int Days { get; private set; } = 0;
public int Hours { get; private set; } = 0;
public int Minutes { get; private set; } = 0;
public int Seconds { get; private set; } = 0;
public int Milliseconds { get; private set; } = 0;
public static DateTimeSpan CompareDates(DateTime StartDate, DateTime EndDate)
{
if (StartDate.Equals(EndDate)) return new DateTimeSpan();
DateTimeSpan R = new DateTimeSpan();
bool Later;
if (Later = StartDate > EndDate)
{
DateTime D = StartDate;
StartDate = EndDate;
EndDate = D;
}
// Calculate Date Stuff
for (DateTime D = StartDate.AddYears(1); D < EndDate; D = D.AddYears(1), R.Years++) ;
if (R.Years > 0) StartDate = StartDate.AddYears(R.Years);
for (DateTime D = StartDate.AddMonths(1); D < EndDate; D = D.AddMonths(1), R.Months++) ;
if (R.Months > 0) StartDate = StartDate.AddMonths(R.Months);
for (DateTime D = StartDate.AddDays(1); D < EndDate; D = D.AddDays(1), R.Days++) ;
if (R.Days > 0) StartDate = StartDate.AddDays(R.Days);
// Calculate Time Stuff
TimeSpan T1 = EndDate - StartDate;
R.Hours = T1.Hours;
R.Minutes = T1.Minutes;
R.Seconds = T1.Seconds;
R.Milliseconds = T1.Milliseconds;
// Return answer. Negate values if the Start Date was later than the End Date
if (Later)
return new DateTimeSpan(-R.Years, -R.Months, -R.Days, -R.Hours, -R.Minutes, -R.Seconds, -R.Milliseconds);
return R;
}
}
Insane method that counts all days, so super precise
helper class :
public class DaysInMonth
{
public int Days { get; set; }
public int Month { get; set; }
public int Year { get; set; }
public bool Full { get; set; }
}
function:
public static List<DaysInMonth> MonthsDelta(DateTime start, DateTime end)
{
var dates = Enumerable.Range(0, 1 + end.Subtract(start).Days)
.Select(offset => start.AddDays(offset))
.ToArray();
DateTime? prev = null;
int days = 0;
List < DaysInMonth > list = new List<DaysInMonth>();
foreach (DateTime date in dates)
{
if (prev != null)
{
if(date.Month!=prev.GetValueOrDefault().Month)
{
DaysInMonth daysInMonth = new DaysInMonth();
daysInMonth.Days = days;
daysInMonth.Month = prev.GetValueOrDefault().Month;
daysInMonth.Year = prev.GetValueOrDefault().Year;
daysInMonth.Full = DateTime.DaysInMonth(daysInMonth.Year, daysInMonth.Month) == daysInMonth.Days;
list.Add(daysInMonth);
days = 0;
}
}
days++;
prev = date;
}
//------------------ add last
if (days > 0)
{
DaysInMonth daysInMonth = new DaysInMonth();
daysInMonth.Days = days;
daysInMonth.Month = prev.GetValueOrDefault().Month;
daysInMonth.Year = prev.GetValueOrDefault().Year;
daysInMonth.Full = DateTime.DaysInMonth(daysInMonth.Year, daysInMonth.Month) == daysInMonth.Days;
list.Add(daysInMonth);
}
return list;
}
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Calculating age from birthday
How do you calculate age in years, taking input from TextBox in the format dd/MM/yyyy?
e.g.
input: txtDOB.Text 20/02/1989 (String format)
output: txtAge.Text 23
You can use the Substract method of DateTime (link) and then use the Days property to determine the actual age:
DateTime now = DateTime.Now;
DateTime givenDate = DateTime.Parse(input);
int days = now.Subtract(givenDate).Days
int age = Math.Floor(days / 365.24219)
TimeSpan TS = DateTime.Now - new DateTime(1989, 02, 20);
double Years = TS.TotalDays / 365.25; // 365 1/4 days per year
As already noted in a comment, the correct answer is here: Calculate age in C#
You just need to get the birthday as a DateTime:
DateTime bday = DateTime.ParseExact("20/02/1989", "dd/MM/yyyy", CultureInfo.InvariantCulture);
The following will work once you have parsed the birth date into a DateTime:
static int AgeInYears(DateTime birthday, DateTime today)
{
return ((today.Year - birthday.Year) * 372 + (today.Month - birthday.Month) * 31 + (today.Day - birthday.Day)) / 372;
}
Parse the date like so:
DateTime dob = DateTime.ParseExact("20/02/1989", "dd/MM/yyyy", CultureInfo.InvariantCulture);
And a sample program:
using System;
namespace Demo
{
class Program
{
static void Main(string[] args)
{
DateTime dob = new DateTime(2010, 12, 30);
DateTime today = DateTime.Now;
int age = AgeInYears(dob, today);
Console.WriteLine(age); // Prints "1"
}
static int AgeInYears(DateTime birthday, DateTime today)
{
return ((today.Year - birthday.Year) * 372 + (today.Month - birthday.Month) * 31 + (today.Day - birthday.Day)) / 372;
}
}
}
This answer isn't the most efficient as it uses a loop, but it doesn't rely on using 365.25 magic numbers either.
A function to return the whole number of years from a datetime to today:
public static int CalcYears(DateTime fromDate)
{
int years = 0;
DateTime toDate = DateTime.Now;
while (toDate.AddYears(-1) >= fromDate)
{
years++;
toDate = toDate.AddYears(-1);
}
return years;
}
Usage:
int age = CalcYears(DateTime.ParseExact(txtDateOfBirth.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture));
var date = DateTime.ParseExact("20/02/1989", "dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture);
var age = (DateTime.Today.Year - date.Year);
Console.WriteLine(age);
Try this
string[] AgeVal=textbox.text.split('/');
string Year=AgeVal[2].tostring();
string CurrentYear= DateTime.Now.Date.Year.ToString();
int Age=Convert.ToInt16((Current))-Convert.ToInt16((Year));
Subtract the two values and get your age.
How to calculate the difference in months between two dates in C#?
Is there is equivalent of VB's DateDiff() method in C#. I need to find difference in months between two dates that are years apart. The documentation says that I can use TimeSpan like:
TimeSpan ts = date1 - date2;
but this gives me data in Days. I don't want to divide this number by 30 because not every month is 30 days and since the two operand values are quite apart from each other, I am afraid dividing by 30 might give me a wrong value.
Any suggestions?
Assuming the day of the month is irrelevant (i.e. the diff between 2011.1.1 and 2010.12.31 is 1), with date1 > date2 giving a positive value and date2 > date1 a negative value
((date1.Year - date2.Year) * 12) + date1.Month - date2.Month
Or, assuming you want an approximate number of 'average months' between the two dates, the following should work for all but very huge date differences.
date1.Subtract(date2).Days / (365.25 / 12)
Note, if you were to use the latter solution then your unit tests should state the widest date range which your application is designed to work with and validate the results of the calculation accordingly.
Update (with thanks to Gary)
If using the 'average months' method, a slightly more accurate number to use for the 'average number of days per year' is 365.2425.
Here is a comprehensive solution to return a DateTimeSpan, similar to a TimeSpan, except that it includes all the date components in addition to the time components.
Usage:
void Main()
{
DateTime compareTo = DateTime.Parse("8/13/2010 8:33:21 AM");
DateTime now = DateTime.Parse("2/9/2012 10:10:11 AM");
var dateSpan = DateTimeSpan.CompareDates(compareTo, now);
Console.WriteLine("Years: " + dateSpan.Years);
Console.WriteLine("Months: " + dateSpan.Months);
Console.WriteLine("Days: " + dateSpan.Days);
Console.WriteLine("Hours: " + dateSpan.Hours);
Console.WriteLine("Minutes: " + dateSpan.Minutes);
Console.WriteLine("Seconds: " + dateSpan.Seconds);
Console.WriteLine("Milliseconds: " + dateSpan.Milliseconds);
}
Outputs:
Years: 1
Months: 5
Days: 27
Hours: 1
Minutes: 36
Seconds: 50
Milliseconds: 0
For convenience, I've lumped the logic into the DateTimeSpan struct, but you may move the method CompareDates wherever you see fit. Also note, it doesn't matter which date comes before the other.
public struct DateTimeSpan
{
public int Years { get; }
public int Months { get; }
public int Days { get; }
public int Hours { get; }
public int Minutes { get; }
public int Seconds { get; }
public int Milliseconds { get; }
public DateTimeSpan(int years, int months, int days, int hours, int minutes, int seconds, int milliseconds)
{
Years = years;
Months = months;
Days = days;
Hours = hours;
Minutes = minutes;
Seconds = seconds;
Milliseconds = milliseconds;
}
enum Phase { Years, Months, Days, Done }
public static DateTimeSpan CompareDates(DateTime date1, DateTime date2)
{
if (date2 < date1)
{
var sub = date1;
date1 = date2;
date2 = sub;
}
DateTime current = date1;
int years = 0;
int months = 0;
int days = 0;
Phase phase = Phase.Years;
DateTimeSpan span = new DateTimeSpan();
int officialDay = current.Day;
while (phase != Phase.Done)
{
switch (phase)
{
case Phase.Years:
if (current.AddYears(years + 1) > date2)
{
phase = Phase.Months;
current = current.AddYears(years);
}
else
{
years++;
}
break;
case Phase.Months:
if (current.AddMonths(months + 1) > date2)
{
phase = Phase.Days;
current = current.AddMonths(months);
if (current.Day < officialDay && officialDay <= DateTime.DaysInMonth(current.Year, current.Month))
current = current.AddDays(officialDay - current.Day);
}
else
{
months++;
}
break;
case Phase.Days:
if (current.AddDays(days + 1) > date2)
{
current = current.AddDays(days);
var timespan = date2 - current;
span = new DateTimeSpan(years, months, days, timespan.Hours, timespan.Minutes, timespan.Seconds, timespan.Milliseconds);
phase = Phase.Done;
}
else
{
days++;
}
break;
}
}
return span;
}
}
You could do
if ( date1.AddMonths(x) > date2 )
If you want the exact number of full months, always positive (2000-01-15, 2000-02-14 returns 0), considering a full month is when you reach the same day the next month (something like the age calculation)
public static int GetMonthsBetween(DateTime from, DateTime to)
{
if (from > to) return GetMonthsBetween(to, from);
var monthDiff = Math.Abs((to.Year * 12 + (to.Month - 1)) - (from.Year * 12 + (from.Month - 1)));
if (from.AddMonths(monthDiff) > to || to.Day < from.Day)
{
return monthDiff - 1;
}
else
{
return monthDiff;
}
}
Edit reason: the old code was not correct in some cases like :
new { From = new DateTime(1900, 8, 31), To = new DateTime(1901, 8, 30), Result = 11 },
Test cases I used to test the function:
var tests = new[]
{
new { From = new DateTime(1900, 1, 1), To = new DateTime(1900, 1, 1), Result = 0 },
new { From = new DateTime(1900, 1, 1), To = new DateTime(1900, 1, 2), Result = 0 },
new { From = new DateTime(1900, 1, 2), To = new DateTime(1900, 1, 1), Result = 0 },
new { From = new DateTime(1900, 1, 1), To = new DateTime(1900, 2, 1), Result = 1 },
new { From = new DateTime(1900, 2, 1), To = new DateTime(1900, 1, 1), Result = 1 },
new { From = new DateTime(1900, 1, 31), To = new DateTime(1900, 2, 1), Result = 0 },
new { From = new DateTime(1900, 8, 31), To = new DateTime(1900, 9, 30), Result = 0 },
new { From = new DateTime(1900, 8, 31), To = new DateTime(1900, 10, 1), Result = 1 },
new { From = new DateTime(1900, 1, 1), To = new DateTime(1901, 1, 1), Result = 12 },
new { From = new DateTime(1900, 1, 1), To = new DateTime(1911, 1, 1), Result = 132 },
new { From = new DateTime(1900, 8, 31), To = new DateTime(1901, 8, 30), Result = 11 },
};
I checked the usage of this method in VB.NET via MSDN and it seems that it has a lot of usages. There is no such a built-in method in C#. (Even it's not a good idea) you can call VB's in C#.
Add Microsoft.VisualBasic.dll to
your project as a reference
use
Microsoft.VisualBasic.DateAndTime.DateDiff
in your code
Use Noda Time:
LocalDate start = new LocalDate(2013, 1, 5);
LocalDate end = new LocalDate(2014, 6, 1);
Period period = Period.Between(start, end, PeriodUnits.Months);
Console.WriteLine(period.Months); // 16
(example source)
To get difference in months (both start and end inclusive), irrespective of dates:
DateTime start = new DateTime(2013, 1, 1);
DateTime end = new DateTime(2014, 2, 1);
var diffMonths = (end.Month + end.Year * 12) - (start.Month + start.Year * 12);
I just needed something simple to cater for e.g. employment dates where only the month/year is entered, so wanted distinct years and months worked in. This is what I use, here for usefullness only
public static YearsMonths YearMonthDiff(DateTime startDate, DateTime endDate) {
int monthDiff = ((endDate.Year * 12) + endDate.Month) - ((startDate.Year * 12) + startDate.Month) + 1;
int years = (int)Math.Floor((decimal) (monthDiff / 12));
int months = monthDiff % 12;
return new YearsMonths {
TotalMonths = monthDiff,
Years = years,
Months = months
};
}
.NET Fiddle
You can use Noda Time https://nodatime.org/
LocalDate start = new LocalDate(2010, 1, 5);
LocalDate end = new LocalDate(2012, 6, 1);
Period period = Period.Between(start, end, PeriodUnits.Months);
Console.WriteLine(period.Months);
You can use the DateDiff class of the Time Period Library for .NET:
// ----------------------------------------------------------------------
public void DateDiffSample()
{
DateTime date1 = new DateTime( 2009, 11, 8, 7, 13, 59 );
DateTime date2 = new DateTime( 2011, 3, 20, 19, 55, 28 );
DateDiff dateDiff = new DateDiff( date1, date2 );
// differences
Console.WriteLine( "DateDiff.Months: {0}", dateDiff.Months );
// > DateDiff.Months: 16
// elapsed
Console.WriteLine( "DateDiff.ElapsedMonths: {0}", dateDiff.ElapsedMonths );
// > DateDiff.ElapsedMonths: 4
// description
Console.WriteLine( "DateDiff.GetDescription(6): {0}", dateDiff.GetDescription( 6 ) );
// > DateDiff.GetDescription(6): 1 Year 4 Months 12 Days 12 Hours 41 Mins 29 Secs
} // DateDiffSample
Here is my contribution to get difference in Months that I've found to be accurate:
namespace System
{
public static class DateTimeExtensions
{
public static Int32 DiffMonths( this DateTime start, DateTime end )
{
Int32 months = 0;
DateTime tmp = start;
while ( tmp < end )
{
months++;
tmp = tmp.AddMonths( 1 );
}
return months;
}
}
}
Usage:
Int32 months = DateTime.Now.DiffMonths( DateTime.Now.AddYears( 5 ) );
You can create another method called DiffYears and apply exactly the same logic as above and AddYears instead of AddMonths in the while loop.
This worked for what I needed it for. The day of month didn't matter in my case because it always happens to be the last day of the month.
public static int MonthDiff(DateTime d1, DateTime d2){
int retVal = 0;
if (d1.Month<d2.Month)
{
retVal = (d1.Month + 12) - d2.Month;
retVal += ((d1.Year - 1) - d2.Year)*12;
}
else
{
retVal = d1.Month - d2.Month;
retVal += (d1.Year - d2.Year)*12;
}
//// Calculate the number of years represented and multiply by 12
//// Substract the month number from the total
//// Substract the difference of the second month and 12 from the total
//retVal = (d1.Year - d2.Year) * 12;
//retVal = retVal - d1.Month;
//retVal = retVal - (12 - d2.Month);
return retVal;
}
There's 3 cases: same year, previous year and other years.
If the day of the month does not matter...
public int GetTotalNumberOfMonths(DateTime start, DateTime end)
{
// work with dates in the right order
if (start > end)
{
var swapper = start;
start = end;
end = swapper;
}
switch (end.Year - start.Year)
{
case 0: // Same year
return end.Month - start.Month;
case 1: // last year
return (12 - start.Month) + end.Month;
default:
return 12 * (3 - (end.Year - start.Year)) + (12 - start.Month) + end.Month;
}
}
The most precise way is this that return difference in months by fraction :
private double ReturnDiffereceBetweenTwoDatesInMonths(DateTime startDateTime, DateTime endDateTime)
{
double result = 0;
double days = 0;
DateTime currentDateTime = startDateTime;
while (endDateTime > currentDateTime.AddMonths(1))
{
result ++;
currentDateTime = currentDateTime.AddMonths(1);
}
if (endDateTime > currentDateTime)
{
days = endDateTime.Subtract(currentDateTime).TotalDays;
}
return result + days/endDateTime.GetMonthDays;
}
My understanding of the total months difference between 2 dates has an integral and a fractional part (the date matters).
The integral part is the full months difference.
The fractional part, for me, is the difference of the % of the day (to the full days of month) between the starting and ending months.
public static class DateTimeExtensions
{
public static double TotalMonthsDifference(this DateTime from, DateTime to)
{
//Compute full months difference between dates
var fullMonthsDiff = (to.Year - from.Year)*12 + to.Month - from.Month;
//Compute difference between the % of day to full days of each month
var fractionMonthsDiff = ((double)(to.Day-1) / (DateTime.DaysInMonth(to.Year, to.Month)-1)) -
((double)(from.Day-1)/ (DateTime.DaysInMonth(from.Year, from.Month)-1));
return fullMonthsDiff + fractionMonthsDiff;
}
}
With this extension, those are the results:
2/29/2000 TotalMonthsDifference 2/28/2001 => 12
2/28/2000 TotalMonthsDifference 2/28/2001 => 12.035714285714286
01/01/2000 TotalMonthsDifference 01/16/2000 => 0.5
01/31/2000 TotalMonthsDifference 01/01/2000 => -1.0
01/31/2000 TotalMonthsDifference 02/29/2000 => 1.0
01/31/2000 TotalMonthsDifference 02/28/2000 => 0.9642857142857143
01/31/2001 TotalMonthsDifference 02/28/2001 => 1.0
Here is a simple solution that works at least for me. It's probably not the fastest though because it uses the cool DateTime's AddMonth feature in a loop:
public static int GetMonthsDiff(DateTime start, DateTime end)
{
if (start > end)
return GetMonthsDiff(end, start);
int months = 0;
do
{
start = start.AddMonths(1);
if (start > end)
return months;
months++;
}
while (true);
}
This simple static function calculates the fraction of months between two Datetimes, e.g.
1.1. to 31.1. = 1.0
1.4. to 15.4. = 0.5
16.4. to 30.4. = 0.5
1.3. to 1.4. = 1 + 1/30
The function assumes that the first date is smaller than the second date. To deal with negative time intervals one can modify the function easily by introducing a sign and a variable swap at the beginning.
public static double GetDeltaMonths(DateTime t0, DateTime t1)
{
DateTime t = t0;
double months = 0;
while(t<=t1)
{
int daysInMonth = DateTime.DaysInMonth(t.Year, t.Month);
DateTime endOfMonth = new DateTime(t.Year, t.Month, daysInMonth);
int cutDay = endOfMonth <= t1 ? daysInMonth : t1.Day;
months += (cutDay - t.Day + 1) / (double) daysInMonth;
t = new DateTime(t.Year, t.Month, 1).AddMonths(1);
}
return Math.Round(months,2);
}
one line solution
For first, check if both dates are in the current year, if not get months of whole years and then add months from the start and end year.
DateTime dateFrom = new DateTime(2019, 2, 1);
DateTime dateTo = new DateTime(2021, 5, 25);
With the first month
var monthCount = dateFrom.Year != dateTo.Year ? ((dateTo.Year - dateFrom.Year - 1) * 12) + (13 - dateFrom.Month + dateTo.Month) : dateTo.Month - dateFrom.Month + 1;
result = 28
Without first month
monthCount = dateFrom.Year != dateTo.Year ? ((dateTo.Year - dateFrom.Year - 1) * 12) + (12 - dateFrom.Month + dateTo.Month) : dateTo.Month - dateFrom.Month;
result = 27
Public Class ClassDateOperation
Private prop_DifferenceInDay As Integer
Private prop_DifferenceInMonth As Integer
Private prop_DifferenceInYear As Integer
Public Function DayMonthYearFromTwoDate(ByVal DateStart As Date, ByVal DateEnd As Date) As ClassDateOperation
Dim differenceInDay As Integer
Dim differenceInMonth As Integer
Dim differenceInYear As Integer
Dim myDate As Date
DateEnd = DateEnd.AddDays(1)
differenceInYear = DateEnd.Year - DateStart.Year
If DateStart.Month <= DateEnd.Month Then
differenceInMonth = DateEnd.Month - DateStart.Month
Else
differenceInYear -= 1
differenceInMonth = (12 - DateStart.Month) + DateEnd.Month
End If
If DateStart.Day <= DateEnd.Day Then
differenceInDay = DateEnd.Day - DateStart.Day
Else
myDate = CDate("01/" & DateStart.AddMonths(1).Month & "/" & DateStart.Year).AddDays(-1)
If differenceInMonth <> 0 Then
differenceInMonth -= 1
Else
differenceInMonth = 11
differenceInYear -= 1
End If
differenceInDay = myDate.Day - DateStart.Day + DateEnd.Day
End If
prop_DifferenceInDay = differenceInDay
prop_DifferenceInMonth = differenceInMonth
prop_DifferenceInYear = differenceInYear
Return Me
End Function
Public ReadOnly Property DifferenceInDay() As Integer
Get
Return prop_DifferenceInDay
End Get
End Property
Public ReadOnly Property DifferenceInMonth As Integer
Get
Return prop_DifferenceInMonth
End Get
End Property
Public ReadOnly Property DifferenceInYear As Integer
Get
Return prop_DifferenceInYear
End Get
End Property
End Class
This is from my own library, will return the difference of months between two dates.
public static int MonthDiff(DateTime d1, DateTime d2)
{
int retVal = 0;
// Calculate the number of years represented and multiply by 12
// Substract the month number from the total
// Substract the difference of the second month and 12 from the total
retVal = (d1.Year - d2.Year) * 12;
retVal = retVal - d1.Month;
retVal = retVal - (12 - d2.Month);
return retVal;
}
You can have a function something like this.
For Example, from 2012/12/27 to 2012/12/29 becomes 3 days. Likewise, from 2012/12/15 to 2013/01/15 becomes 2 months, because up to 2013/01/14 it's 1 month. from 15th it's 2nd month started.
You can remove the "=" in the second if condition, if you do not want to include both days in the calculation. i.e, from 2012/12/15 to 2013/01/15 is 1 month.
public int GetMonths(DateTime startDate, DateTime endDate)
{
if (startDate > endDate)
{
throw new Exception("Start Date is greater than the End Date");
}
int months = ((endDate.Year * 12) + endDate.Month) - ((startDate.Year * 12) + startDate.Month);
if (endDate.Day >= startDate.Day)
{
months++;
}
return months;
}
you can use the following extension:
Code
public static class Ext
{
#region Public Methods
public static int GetAge(this DateTime #this)
{
var today = DateTime.Today;
return ((((today.Year - #this.Year) * 100) + (today.Month - #this.Month)) * 100 + today.Day - #this.Day) / 10000;
}
public static int DiffMonths(this DateTime #from, DateTime #to)
{
return (((((#to.Year - #from.Year) * 12) + (#to.Month - #from.Month)) * 100 + #to.Day - #from.Day) / 100);
}
public static int DiffYears(this DateTime #from, DateTime #to)
{
return ((((#to.Year - #from.Year) * 100) + (#to.Month - #from.Month)) * 100 + #to.Day - #from.Day) / 10000;
}
#endregion Public Methods
}
Implementation !
int Age;
int years;
int Months;
//Replace your own date
var d1 = new DateTime(2000, 10, 22);
var d2 = new DateTime(2003, 10, 20);
//Age
Age = d1.GetAge();
Age = d2.GetAge();
//positive
years = d1.DiffYears(d2);
Months = d1.DiffMonths(d2);
//negative
years = d2.DiffYears(d1);
Months = d2.DiffMonths(d1);
//Or
Months = Ext.DiffMonths(d1, d2);
years = Ext.DiffYears(d1, d2);
Here's a much more concise solution using VB.Net DateDiff for Year, Month, Day only. You can load the DateDiff library in C# as well.
date1 must be <= date2
VB.NET
Dim date1 = Now.AddDays(-2000)
Dim date2 = Now
Dim diffYears = DateDiff(DateInterval.Year, date1, date2) - If(date1.DayOfYear > date2.DayOfYear, 1, 0)
Dim diffMonths = DateDiff(DateInterval.Month, date1, date2) - diffYears * 12 - If(date1.Day > date2.Day, 1, 0)
Dim diffDays = If(date2.Day >= date1.Day, date2.Day - date1.Day, date2.Day + (Date.DaysInMonth(date1.Year, date1.Month) - date1.Day))
C#
DateTime date1 = Now.AddDays(-2000);
DateTime date2 = Now;
int diffYears = DateDiff(DateInterval.Year, date1, date2) - date1.DayOfYear > date2.DayOfYear ? 1 : 0;
int diffMonths = DateDiff(DateInterval.Month, date1, date2) - diffYears * 12 - date1.Day > date2.Day ? 1 : 0;
int diffDays = date2.Day >= date1.Day ? date2.Day - date1.Day : date2.Day + (System.DateTime.DaysInMonth(date1.Year, date1.Month) - date1.Day);
This is in response to Kirk Woll's answer. I don't have enough reputation points to reply to a comment yet...
I liked Kirk's solution and was going to shamelessly rip it off and use it in my code, but when I looked through it I realized it's way too complicated. Unnecessary switching and looping, and a public constructor that is pointless to use.
Here's my rewrite:
public class DateTimeSpan {
private DateTime _date1;
private DateTime _date2;
private int _years;
private int _months;
private int _days;
private int _hours;
private int _minutes;
private int _seconds;
private int _milliseconds;
public int Years { get { return _years; } }
public int Months { get { return _months; } }
public int Days { get { return _days; } }
public int Hours { get { return _hours; } }
public int Minutes { get { return _minutes; } }
public int Seconds { get { return _seconds; } }
public int Milliseconds { get { return _milliseconds; } }
public DateTimeSpan(DateTime date1, DateTime date2) {
_date1 = (date1 > date2) ? date1 : date2;
_date2 = (date2 < date1) ? date2 : date1;
_years = _date1.Year - _date2.Year;
_months = (_years * 12) + _date1.Month - _date2.Month;
TimeSpan t = (_date2 - _date1);
_days = t.Days;
_hours = t.Hours;
_minutes = t.Minutes;
_seconds = t.Seconds;
_milliseconds = t.Milliseconds;
}
public static DateTimeSpan CompareDates(DateTime date1, DateTime date2) {
return new DateTimeSpan(date1, date2);
}
}
Usage1, pretty much the same:
void Main()
{
DateTime compareTo = DateTime.Parse("8/13/2010 8:33:21 AM");
DateTime now = DateTime.Parse("2/9/2012 10:10:11 AM");
var dateSpan = new DateTimeSpan(compareTo, now);
Console.WriteLine("Years: " + dateSpan.Years);
Console.WriteLine("Months: " + dateSpan.Months);
Console.WriteLine("Days: " + dateSpan.Days);
Console.WriteLine("Hours: " + dateSpan.Hours);
Console.WriteLine("Minutes: " + dateSpan.Minutes);
Console.WriteLine("Seconds: " + dateSpan.Seconds);
Console.WriteLine("Milliseconds: " + dateSpan.Milliseconds);
}
Usage2, similar:
void Main()
{
DateTime compareTo = DateTime.Parse("8/13/2010 8:33:21 AM");
DateTime now = DateTime.Parse("2/9/2012 10:10:11 AM");
Console.WriteLine("Years: " + DateTimeSpan.CompareDates(compareTo, now).Years);
Console.WriteLine("Months: " + DateTimeSpan.CompareDates(compareTo, now).Months);
Console.WriteLine("Days: " + DateTimeSpan.CompareDates(compareTo, now).Days);
Console.WriteLine("Hours: " + DateTimeSpan.CompareDates(compareTo, now).Hours);
Console.WriteLine("Minutes: " + DateTimeSpan.CompareDates(compareTo, now).Minutes);
Console.WriteLine("Seconds: " + DateTimeSpan.CompareDates(compareTo, now).Seconds);
Console.WriteLine("Milliseconds: " + DateTimeSpan.CompareDates(compareTo, now).Milliseconds);
}
In my case it is required to calculate the complete month from the start date to the day prior to this day in the next month or from start to end of month.
Ex: from 1/1/2018 to 31/1/2018 is a complete month
Ex2: from 5/1/2018 to 4/2/2018 is a complete month
so based on this here is my solution:
public static DateTime GetMonthEnd(DateTime StartDate, int MonthsCount = 1)
{
return StartDate.AddMonths(MonthsCount).AddDays(-1);
}
public static Tuple<int, int> CalcPeriod(DateTime StartDate, DateTime EndDate)
{
int MonthsCount = 0;
Tuple<int, int> Period;
while (true)
{
if (GetMonthEnd(StartDate) > EndDate)
break;
else
{
MonthsCount += 1;
StartDate = StartDate.AddMonths(1);
}
}
int RemainingDays = (EndDate - StartDate).Days + 1;
Period = new Tuple<int, int>(MonthsCount, RemainingDays);
return Period;
}
Usage:
Tuple<int, int> Period = CalcPeriod(FromDate, ToDate);
Note: in my case it was required to calculate the remaining days after the complete months so if it's not your case you could ignore the days result or even you could change the method return from tuple to integer.
public static int PayableMonthsInDuration(DateTime StartDate, DateTime EndDate)
{
int sy = StartDate.Year; int sm = StartDate.Month; int count = 0;
do
{
count++;if ((sy == EndDate.Year) && (sm >= EndDate.Month)) { break; }
sm++;if (sm == 13) { sm = 1; sy++; }
} while ((EndDate.Year >= sy) || (EndDate.Month >= sm));
return (count);
}
This solution is for Rental/subscription calculation, where difference doesn't means to be subtraction, it's meant to be the span in within those two dates.
I wrote a function to accomplish this, because the others ways weren't working for me.
public string getEndDate (DateTime startDate,decimal monthCount)
{
int y = startDate.Year;
int m = startDate.Month;
for (decimal i = monthCount; i > 1; i--)
{
m++;
if (m == 12)
{ y++;
m = 1;
}
}
return string.Format("{0}-{1}-{2}", y.ToString(), m.ToString(), startDate.Day.ToString());
}
There are not a lot of clear answers on this because you are always assuming things.
This solution calculates between two dates the months between assuming you want to save the day of month for comparison, (meaning that the day of the month is considered in the calculation)
Example, if you have a date of 30 Jan 2012, 29 Feb 2012 will not be a month but 01 March 2013 will.
It's been tested pretty thoroughly, probably will clean it up later as we use it, but here:
private static int TotalMonthDifference(DateTime dtThis, DateTime dtOther)
{
int intReturn = 0;
bool sameMonth = false;
if (dtOther.Date < dtThis.Date) //used for an error catch in program, returns -1
intReturn--;
int dayOfMonth = dtThis.Day; //captures the month of day for when it adds a month and doesn't have that many days
int daysinMonth = 0; //used to caputre how many days are in the month
while (dtOther.Date > dtThis.Date) //while Other date is still under the other
{
dtThis = dtThis.AddMonths(1); //as we loop, we just keep adding a month for testing
daysinMonth = DateTime.DaysInMonth(dtThis.Year, dtThis.Month); //grabs the days in the current tested month
if (dtThis.Day != dayOfMonth) //Example 30 Jan 2013 will go to 28 Feb when a month is added, so when it goes to march it will be 28th and not 30th
{
if (daysinMonth < dayOfMonth) // uses day in month max if can't set back to day of month
dtThis.AddDays(daysinMonth - dtThis.Day);
else
dtThis.AddDays(dayOfMonth - dtThis.Day);
}
if (((dtOther.Year == dtThis.Year) && (dtOther.Month == dtThis.Month))) //If the loop puts it in the same month and year
{
if (dtOther.Day >= dayOfMonth) //check to see if it is the same day or later to add one to month
intReturn++;
sameMonth = true; //sets this to cancel out of the normal counting of month
}
if ((!sameMonth)&&(dtOther.Date > dtThis.Date))//so as long as it didn't reach the same month (or if i started in the same month, one month ahead, add a month)
intReturn++;
}
return intReturn; //return month
}
Based on the excellent DateTimeSpan work done above, I've normalized the code a bit; this seems to work pretty well:
public class DateTimeSpan
{
private DateTimeSpan() { }
private DateTimeSpan(int years, int months, int days, int hours, int minutes, int seconds, int milliseconds)
{
Years = years;
Months = months;
Days = days;
Hours = hours;
Minutes = minutes;
Seconds = seconds;
Milliseconds = milliseconds;
}
public int Years { get; private set; } = 0;
public int Months { get; private set; } = 0;
public int Days { get; private set; } = 0;
public int Hours { get; private set; } = 0;
public int Minutes { get; private set; } = 0;
public int Seconds { get; private set; } = 0;
public int Milliseconds { get; private set; } = 0;
public static DateTimeSpan CompareDates(DateTime StartDate, DateTime EndDate)
{
if (StartDate.Equals(EndDate)) return new DateTimeSpan();
DateTimeSpan R = new DateTimeSpan();
bool Later;
if (Later = StartDate > EndDate)
{
DateTime D = StartDate;
StartDate = EndDate;
EndDate = D;
}
// Calculate Date Stuff
for (DateTime D = StartDate.AddYears(1); D < EndDate; D = D.AddYears(1), R.Years++) ;
if (R.Years > 0) StartDate = StartDate.AddYears(R.Years);
for (DateTime D = StartDate.AddMonths(1); D < EndDate; D = D.AddMonths(1), R.Months++) ;
if (R.Months > 0) StartDate = StartDate.AddMonths(R.Months);
for (DateTime D = StartDate.AddDays(1); D < EndDate; D = D.AddDays(1), R.Days++) ;
if (R.Days > 0) StartDate = StartDate.AddDays(R.Days);
// Calculate Time Stuff
TimeSpan T1 = EndDate - StartDate;
R.Hours = T1.Hours;
R.Minutes = T1.Minutes;
R.Seconds = T1.Seconds;
R.Milliseconds = T1.Milliseconds;
// Return answer. Negate values if the Start Date was later than the End Date
if (Later)
return new DateTimeSpan(-R.Years, -R.Months, -R.Days, -R.Hours, -R.Minutes, -R.Seconds, -R.Milliseconds);
return R;
}
}
Insane method that counts all days, so super precise
helper class :
public class DaysInMonth
{
public int Days { get; set; }
public int Month { get; set; }
public int Year { get; set; }
public bool Full { get; set; }
}
function:
public static List<DaysInMonth> MonthsDelta(DateTime start, DateTime end)
{
var dates = Enumerable.Range(0, 1 + end.Subtract(start).Days)
.Select(offset => start.AddDays(offset))
.ToArray();
DateTime? prev = null;
int days = 0;
List < DaysInMonth > list = new List<DaysInMonth>();
foreach (DateTime date in dates)
{
if (prev != null)
{
if(date.Month!=prev.GetValueOrDefault().Month)
{
DaysInMonth daysInMonth = new DaysInMonth();
daysInMonth.Days = days;
daysInMonth.Month = prev.GetValueOrDefault().Month;
daysInMonth.Year = prev.GetValueOrDefault().Year;
daysInMonth.Full = DateTime.DaysInMonth(daysInMonth.Year, daysInMonth.Month) == daysInMonth.Days;
list.Add(daysInMonth);
days = 0;
}
}
days++;
prev = date;
}
//------------------ add last
if (days > 0)
{
DaysInMonth daysInMonth = new DaysInMonth();
daysInMonth.Days = days;
daysInMonth.Month = prev.GetValueOrDefault().Month;
daysInMonth.Year = prev.GetValueOrDefault().Year;
daysInMonth.Full = DateTime.DaysInMonth(daysInMonth.Year, daysInMonth.Month) == daysInMonth.Days;
list.Add(daysInMonth);
}
return list;
}
This question already has answers here:
How do I calculate someone's age based on a DateTime type birthday?
(74 answers)
Closed 6 years ago.
How can I calculate date difference between two dates in years?
For example: (Datetime.Now.Today() - 11/03/2007) in years.
I have written an implementation that properly works with dates exactly one year apart.
However, it does not gracefully handle negative timespans, unlike the other algorithm. It also doesn't use its own date arithmetic, instead relying upon the standard library for that.
So without further ado, here is the code:
DateTime zeroTime = new DateTime(1, 1, 1);
DateTime a = new DateTime(2007, 1, 1);
DateTime b = new DateTime(2008, 1, 1);
TimeSpan span = b - a;
// Because we start at year 1 for the Gregorian
// calendar, we must subtract a year here.
int years = (zeroTime + span).Year - 1;
// 1, where my other algorithm resulted in 0.
Console.WriteLine("Yrs elapsed: " + years);
Use:
int Years(DateTime start, DateTime end)
{
return (end.Year - start.Year - 1) +
(((end.Month > start.Month) ||
((end.Month == start.Month) && (end.Day >= start.Day))) ? 1 : 0);
}
We had to code a check to establish if the difference between two dates, a start and end date was greater than 2 years.
Thanks to the tips above it was done as follows:
DateTime StartDate = Convert.ToDateTime("01/01/2012");
DateTime EndDate = Convert.ToDateTime("01/01/2014");
DateTime TwoYears = StartDate.AddYears(2);
if EndDate > TwoYears .....
If you need it for knowing someone's age for trivial reasons then Timespan is OK but if you need for calculating superannuation, long term deposits or anything else for financial, scientific or legal purposes then I'm afraid Timespan won't be accurate enough because Timespan assumes that every year has the same number of days, same # of hours and same # of seconds).
In reality the length of some years will vary (for different reasons that are outside the scope of this answer). To get around Timespan's limitation then you can mimic what Excel does which is:
public int GetDifferenceInYears(DateTime startDate, DateTime endDate)
{
//Excel documentation says "COMPLETE calendar years in between dates"
int years = endDate.Year - startDate.Year;
if (startDate.Month == endDate.Month &&// if the start month and the end month are the same
endDate.Day < startDate.Day// AND the end day is less than the start day
|| endDate.Month < startDate.Month)// OR if the end month is less than the start month
{
years--;
}
return years;
}
var totalYears =
(DateTime.Today - new DateTime(2007, 03, 11)).TotalDays
/ 365.2425;
Average days from Wikipedia/Leap_year.
int Age = new DateTime((DateTime.Now - BirthDateTime).Ticks).Year;
To calculate the elapsed years (age), the result will be minus one.
var timeSpan = DateTime.Now - birthDateTime;
int age = new DateTime(timeSpan.Ticks).Year - 1;
Here is a neat trick which lets the system deal with leap years automagically. It gives an accurate answer for all date combinations.
DateTime dt1 = new DateTime(1987, 9, 23, 13, 12, 12, 0);
DateTime dt2 = new DateTime(2007, 6, 15, 16, 25, 46, 0);
DateTime tmp = dt1;
int years = -1;
while (tmp < dt2)
{
years++;
tmp = tmp.AddYears(1);
}
Console.WriteLine("{0}", years);
It's unclear how you want to handle fractional years, but perhaps like this:
DateTime now = DateTime.Now;
DateTime origin = new DateTime(2007, 11, 3);
int calendar_years = now.Year - origin.Year;
int whole_years = calendar_years - ((now.AddYears(-calendar_years) >= origin)? 0: 1);
int another_method = calendar_years - ((now.Month - origin.Month) * 32 >= origin.Day - now.Day)? 0: 1);
I implemented an extension method to get the number of years between two dates, rounded by whole months.
/// <summary>
/// Gets the total number of years between two dates, rounded to whole months.
/// Examples:
/// 2011-12-14, 2012-12-15 returns 1.
/// 2011-12-14, 2012-12-14 returns 1.
/// 2011-12-14, 2012-12-13 returns 0,9167.
/// </summary>
/// <param name="start">
/// Stardate of time period
/// </param>
/// <param name="end">
/// Enddate of time period
/// </param>
/// <returns>
/// Total Years between the two days
/// </returns>
public static double DifferenceTotalYears(this DateTime start, DateTime end)
{
// Get difference in total months.
int months = ((end.Year - start.Year) * 12) + (end.Month - start.Month);
// substract 1 month if end month is not completed
if (end.Day < start.Day)
{
months--;
}
double totalyears = months / 12d;
return totalyears;
}
public string GetAgeText(DateTime birthDate)
{
const double ApproxDaysPerMonth = 30.4375;
const double ApproxDaysPerYear = 365.25;
int iDays = (DateTime.Now - birthDate).Days;
int iYear = (int)(iDays / ApproxDaysPerYear);
iDays -= (int)(iYear * ApproxDaysPerYear);
int iMonths = (int)(iDays / ApproxDaysPerMonth);
iDays -= (int)(iMonths * ApproxDaysPerMonth);
return string.Format("{0} år, {1} måneder, {2} dage", iYear, iMonths, iDays);
}
I found this at TimeSpan for years, months and days:
DateTime target_dob = THE_DOB;
DateTime true_age = DateTime.MinValue + ((TimeSpan)(DateTime.Now - target_dob )); // Minimum value as 1/1/1
int yr = true_age.Year - 1;
If you're dealing with months and years you need something that knows how many days each month has and which years are leap years.
Enter the Gregorian Calendar (and other culture-specific Calendar implementations).
While Calendar doesn't provide methods to directly calculate the difference between two points in time, it does have methods such as
DateTime AddWeeks(DateTime time, int weeks)
DateTime AddMonths(DateTime time, int months)
DateTime AddYears(DateTime time, int years)
DateTime musteriDogum = new DateTime(dogumYil, dogumAy, dogumGun);
int additionalDays = ((DateTime.Now.Year - dogumYil) / 4); //Count of the years with 366 days
int extraDays = additionalDays + ((DateTime.Now.Year % 4 == 0 || musteriDogum.Year % 4 == 0) ? 1 : 0); //We add 1 if this year or year inserted has 366 days
int yearsOld = ((DateTime.Now - musteriDogum).Days - extraDays ) / 365; // Now we extract these extra days from total days and we can divide to 365
Works perfect:
internal static int GetDifferenceInYears(DateTime startDate)
{
int finalResult = 0;
const int DaysInYear = 365;
DateTime endDate = DateTime.Now;
TimeSpan timeSpan = endDate - startDate;
if (timeSpan.TotalDays > 365)
{
finalResult = (int)Math.Round((timeSpan.TotalDays / DaysInYear), MidpointRounding.ToEven);
}
return finalResult;
}
Simple solution:
public int getYearDiff(DateTime startDate, DateTime endDate){
int y = Year(endDate) - Year(startDate);
int startMonth = Month(startDate);
int endMonth = Month(endDate);
if (endMonth < startMonth)
return y - 1;
if (endMonth > startMonth)
return y;
return (Day(endDate) < Day(startDate) ? y - 1 : y);
}
This is the best code to calculate year and month difference:
DateTime firstDate = DateTime.Parse("1/31/2019");
DateTime secondDate = DateTime.Parse("2/1/2016");
int totalYears = firstDate.Year - secondDate.Year;
int totalMonths = 0;
if (firstDate.Month > secondDate.Month)
totalMonths = firstDate.Month - secondDate.Month;
else if (firstDate.Month < secondDate.Month)
{
totalYears -= 1;
int monthDifference = secondDate.Month - firstDate.Month;
totalMonths = 12 - monthDifference;
}
if ((firstDate.Day - secondDate.Day) == 30)
{
totalMonths += 1;
if (totalMonths % 12 == 0)
{
totalYears += 1;
totalMonths = 0;
}
}
Maybe this will be helpful for answering the question: Count of days in given year,
new DateTime(anyDate.Year, 12, 31).DayOfYear //will include leap years too
Regarding DateTime.DayOfYear Property.
The following is based off Dana's simple code which produces the correct answer in most cases. But it did not take in to account less than a year between dates. So here is the code that I use to produce consistent results:
public static int DateDiffYears(DateTime startDate, DateTime endDate)
{
var yr = endDate.Year - startDate.Year - 1 +
(endDate.Month >= startDate.Month && endDate.Day >= startDate.Day ? 1 : 0);
return yr < 0 ? 0 : yr;
}