I am using DateTime.TryParse() function to check if a particular string is a valid datetime not depending on any cultures.
To my surprise , the function returns true for even strings like "1-1", "1/1" .etc.
How can I solve this problem?
Update:
Does it mean, if I want to check if a particular string is valid datetime, I need a huge array of formats?? There will be different combinations , I believe.
Even there are lots of date separator ( '.' , '/' , '-', etc..) depending on the culture, it will be difficult for me to define an array of format to check against .
Basically, I want to check if a particular string contains AT LEAST day(1 through 31 or 01 through 31),month(1 through 12 or 01 through 12) and year(yyyy or yy) in any order, with any date separator , what will be the solution?
So, if the value includes any parts of time, it should return true too.
I could NOT be able to define a array of format.
If you want your dates to conform a particular format or formats then use DateTime.TryParseExact otherwise that is the default behaviour of DateTime.TryParse
DateTime.TryParse
This method tries to ignore unrecognized data, if possible, and
fills in missing month, day, and year information with the current
date. If s contains only a date and no time, this method assumes the
time is 12:00 midnight. If s includes a date component with a
two-digit year, it is converted to a year in the current culture's
current calendar based on the value of the Calendar.TwoDigitYearMax
property. Any leading, inner, or trailing white space character in s
is ignored.
If you want to confirm against multiple formats then look at DateTime.TryParseExact Method (String, String[], IFormatProvider, DateTimeStyles, DateTime) overload. Example from the same link:
string[] formats= {"M/d/yyyy h:mm:ss tt", "M/d/yyyy h:mm tt",
"MM/dd/yyyy hh:mm:ss", "M/d/yyyy h:mm:ss",
"M/d/yyyy hh:mm tt", "M/d/yyyy hh tt",
"M/d/yyyy h:mm", "M/d/yyyy h:mm",
"MM/dd/yyyy hh:mm", "M/dd/yyyy hh:mm"};
string[] dateStrings = {"5/1/2009 6:32 PM", "05/01/2009 6:32:05 PM",
"5/1/2009 6:32:00", "05/01/2009 06:32",
"05/01/2009 06:32:00 PM", "05/01/2009 06:32:00"};
DateTime dateValue;
foreach (string dateString in dateStrings)
{
if (DateTime.TryParseExact(dateString, formats,
new CultureInfo("en-US"),
DateTimeStyles.None,
out dateValue))
Console.WriteLine("Converted '{0}' to {1}.", dateString, dateValue);
else
Console.WriteLine("Unable to convert '{0}' to a date.", dateString);
}
// The example displays the following output:
// Converted '5/1/2009 6:32 PM' to 5/1/2009 6:32:00 PM.
// Converted '05/01/2009 6:32:05 PM' to 5/1/2009 6:32:05 PM.
// Converted '5/1/2009 6:32:00' to 5/1/2009 6:32:00 AM.
// Converted '05/01/2009 06:32' to 5/1/2009 6:32:00 AM.
// Converted '05/01/2009 06:32:00 PM' to 5/1/2009 6:32:00 PM.
// Converted '05/01/2009 06:32:00' to 5/1/2009 6:32:00 AM.
Use DateTime.TryParseExact() if you want to match against a specific date format
string format = "ddd dd MMM h:mm tt yyyy";
DateTime dateTime;
if (DateTime.TryParseExact(dateString, format, CultureInfo.InvariantCulture,
DateTimeStyles.None, out dateTime))
{
Console.WriteLine(dateTime);
}
else
{
Console.WriteLine("Not a date");
}
[TestCase("11/08/1995", Result= true)]
[TestCase("1-1", Result = false)]
[TestCase("1/1", Result = false)]
public bool IsValidDateTimeTest(string dateTime)
{
string[] formats = { "MM/dd/yyyy" };
DateTime parsedDateTime;
return DateTime.TryParseExact(dateTime, formats, new CultureInfo("en-US"),
DateTimeStyles.None, out parsedDateTime);
}
Simply specify the date time formats that you wish to accept in the array named formats.
So this question has been answered but to me the code used is not simple enough or complete. To me this bit here is what I was looking for and possibly some other people will like this as well.
string dateString = "198101";
if (DateTime.TryParse(dateString, out DateTime Temp) == true)
{
//do stuff
}
The output is stored in Temp and not needed afterwards, datestring is the input string to be tested.
An alternative is to create a method to validate that the text is of Date type.
public bool IsDateTime(string date)
{
if (string.IsNullOrEmpty(date)) return false;
return DateTime.TryParse(date, out DateTime dateTime);
}
Basically, I want to check if a particular string contains AT LEAST day(1 through 31 or 01 through 31),month(1 through 12 or 01 through 12) and year(yyyy or yy) in any order, with any date separator , what will be the solution?
So, if the value includes any parts of time, it should return true too. I could NOT be able to define a array of format.
When I was in a similar situation, here is what I did:
Gather all the formats my system is expected to support.
Looked at what is common or can be generalize.
Learned to create REGEX (It is an investment of time initially but pays off once you create one or two on your own). Also do not try to build REGEX for all formats in one go, follow incremental process.
I created REGEX to cover as many format as possible.
For few cases, not to make REGEX extra complex, I covered it through DateTime.Parse() method.
With the combination of both Parse as well as REGEX i was able to validate the input is correct/as expected.
This http://www.codeproject.com/Articles/13255/Validation-with-Regular-Expressions-Made-Simple
was really helpful both for understanding as well as validation the syntax for each format.
My 2 cents if it helps....
Try using
DateTime.ParseExact(
txtPaymentSummaryBeginDate.Text.Trim(),
"MM/dd/yyyy",
System.Globalization.CultureInfo.InvariantCulture
);
It throws an exception if the input string is not in proper format, so in the catch section you can return false;
Related
I am trying to convert to time from a string
My string are like this "11:45 AM" or "03:19 PM" and i am using
dateTime = DateTime.ParseExact("11:45 AM", "H:mm tt",
System.Globalization.CultureInfo.InvariantCulture);
Then it is getting converted but when i am passing
DateTime.ParseExact("3:19 PM", "H:mm tt",
System.Globalization.CultureInfo.InvariantCulture).ToString();
Getting error as
String was not recognized as a valid DateTime.
I cant understand why it is happening any one have idea then please help me
I would use h instead of H. H is for the 24hr fromat, h for the 12hr format.
DateTime.ParseExact("9:45 PM", "h:mm tt", System.Globalization.CultureInfo.InvariantCulture)
See the full list of format options here.
As you want to parse the 12 hr format and convert it to the 24 hr format then you can just use this
string dt = DateTime.ParseExact("3:19 PM", "h:mm tt",CultureInfo.InvariantCulture).ToString("HH:mm");;
Unfortunately, none of the answers are completely correct.
Ante meridiem and post meridiem belong to the 12-hour clock format. That's why you should never use 24-hour clock format specifiers if your string contains one of them.
That's why you need to use h or hh specifiers, not H or HH. Since your hour part can be with leading zeros, using hh specifier is the best option for both of your string types.
Using the hh:mm tt format will parse your strings successfully.
string s = "03:19 PM";
DateTime dt;
if(DateTime.TryParseExact(s, "hh:mm tt", CultureInfo.InvariantCulture,
DateTimeStyles.None, out dt))
{
dt.Dump(); // 29.05.2015 15:19:00
}
and
string s = "11:45 AM";
DateTime dt;
if(DateTime.TryParseExact(s, "hh:mm tt", CultureInfo.InvariantCulture,
DateTimeStyles.None, out dt))
{
dt.Dump(); // 29.05.2015 11:45:00
}
Also, you mentioned the 3:19 PM string in your code example. Since the hour part is single digit, you need to use the h:mm tt format in that case.
Invariant culture requires two-digit hours.
I have two Timestamps that are saved to and read from two XML files.
Currently I am reading the timestamps from the xml files in a WCF Service method, so they are coming in as Strings , but I need them to be converted into DateTime so they can be compared.
The obvious Convert.ToDateTime(TimeStampString) renders this error at Runtime -
String was not recognized as a valid DateTime
As does
DateTime.ParseExact(TimeStampString, "mm/dd/yyyy hh:MM:ss", CultureInfo.InvariantCulture);
Both Timestamps are in the correct format for DateTime (mm/dd/yyyy hh:MM:ss).
I've even tried splitting the timstamp strings into String[] and assembling my own DateTime object by hand, and I still received the error.
Is this a format issue? How can I make my String a valid DateTime?
It's a format issue
mm/dd/yy hh:MM:ss
should be
MM/dd/yyyy hh:mm:ss
(basically, swap the upper case MM in the date & the lowercase mm in the time)
I resolved the issue by removing any attempts to alter the format from US, so Strings came in with US format - then used an IFormatProvider to alter the format at conversion time.
IFormatProvider localFormat = new System.Globalization.CultureInfo("fr-FR", true);
DateTime ContentLastUpdatedTime = DateTime.Parse(ContentLastUpdatedStamp, localFormat , System.Globalization.DateTimeStyles.AssumeLocal);
DateTime ContentLastGrabbedTime = DateTime.Parse(LastGrabbedTimeStamp, localFormat , System.Globalization.DateTimeStyles.AssumeLocal);
You need to use
DateTime.ParseExact(TimeStampString, "MM/dd/yyyy hh:mm:ss", CultureInfo.InvariantCulture);
instead of
DateTime.ParseExact(TimeStampString, "mm/dd/yyyy hh:MM:ss", CultureInfo.InvariantCulture);
The issue is lower case mm which is used for minutes, You need MM upper case MM, plus your date is in 24 hours format, and you need upper case HH for hour part , so your format should be:
MM/dd/yyyy HH:mm:ss
(considering you have yyyy in your original code based on your comment)
See: Custom Date and Time Format Strings
Here you go
var dtedatetime = DateTime.Now.ToString("yyyy-MM-ddTHH:mm:sszzz");
DateTimeOffset dto;
bool bIsParsed = DateTimeOffset.TryParseExact(dtedatetime , "yyyy'-'MM'-'dd'T'HH':'mm':'sszzz",
System.Globalization.CultureInfo.InvariantCulture,
DateTimeStyles.AdjustToUniversal, out dto);
var result = dto.DateTime;
I have a custom date format that I want to convert to Datetime so I can then insert into my database, I tried using Datetime.ParseExact() But I think I'm misunderstanding something as the code throws a System.FormatException.
I have the following date format from a csv
> 6/11/2014 9:00
and I wish to convert it to the mysql datetime format
> 0000-00-00 00:00:00 OR yyyy-MM-dd HH:mm:ss
Notice they haven't included the seconds in the original date so I am unsure (without appending them to the end) how to set all records to just have "00" for seconds as it is not available.
I tried the following which throws an exception
DateTime myDate = DateTime.ParseExact("6/11/2014 9:00", "yyyy-MM-dd HH:mm",
System.Globalization.CultureInfo.InvariantCulture);
first thing you need to convert string to date time and than convert datetime tos tring
string strd = "6/11/2014 9:00";
DateTime dt ;
//convert datetime string to datetime
if(DateTime.TryParse(strd, out dt))
{
//convert datetime to custom datetime format
Console.WriteLine("The current date and time: {0: yyyy-MM-dd HH:mm:ss}",
dt); ;
}
output
I know this is late to answer that but I'm really surprised none of answer consider to use IFormatProvider to prevent a possible parsing error because of / format specifier or considering your string is a standard date and time format for your CurrentCulture or not so you can or can't use DateTime.TryParse(string, out DateTime) overload directly.
First of all, let's look at what DateTime.ParseExact documentation says:
Converts the specified string representation of a date and time to its
DateTime equivalent. The format of the string representation must
match a specified format exactly or an exception is thrown.
In your case, they don't match. You should use d/MM/yyyy H:mm format to parse your example string with a culture that have / as a DateSeparator. I almost always suggest to use DateTime.TryParseExact method in this kind of situations;
string s = "6/11/2014 9:00";
DateTime dt;
if(DateTime.TryParseExact(s, "d/MM/yyyy H:mm", CultureInfo.InvariantCulture,
DateTimeStyles.None, out dt))
{
Console.WriteLine(dt.ToString("yyyy-MM-dd HH:mm:ss"));
// result will be 2014-11-06 09:00:00
}
If you know formats of your dates, then you can do this:
string stringDate = "6/11/2014 9:00";
//Your date formats of input
string[] dateFormats = new string[]
{
"d/MM/yyyy H:mm",
"dd/MM/yyyy H:mm",
"dd/MM/yyyy HH:mm",
"dd/MM/yyyy H:mm:ss",
"dd/MM/yyyy HH:mm:ss"
/* And other formats */
};
DateTime convertedDate;
bool isSuccessful = DateTime.TryParseExact(stringDate, dateFormats,
System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.None, out convertedDate);
if (isSuccessful)
{
//If conversion was successful then you can print your date at any format you like
//because you have your date as DateTime object
Console.WriteLine(convertedDate.ToString("dd-MM-yyyy HH:mm:ss")); /* Or other format you want to print */
}
I hope it will be helpful to you.
I want to format the input string into MM/dd/yyyy hh:mm:ss format in C#.
The input string is in format MM/dd/yyyy hh:mm:ss
For example :"04/30/2013 23:00"
I tried Convert.ToDateTime() function, but it considers 4 as date and 3 as month which is not what I want. Actually month is 04 and date is 03.
I tried DateTime.ParseExact() function also, But getting Exception.
I am getting error:
String was not recognized as a valid DateTime.
Your date time string doesn't contains any seconds. You need to reflect that in your format (remove the :ss).
Also, you need to specify H instead of h if you are using 24 hour times:
DateTime.ParseExact("04/30/2013 23:00", "MM/dd/yyyy HH:mm", CultureInfo.InvariantCulture)
See here for more information:
Custom Date and Time Format Strings
You can use DateTime.ParseExact() method.
Converts the specified string representation of a date and time to its
DateTime equivalent using the specified format and culture-specific
format information. The format of the string representation must match
the specified format exactly.
DateTime date = DateTime.ParseExact("04/30/2013 23:00",
"MM/dd/yyyy HH:mm",
CultureInfo.InvariantCulture);
Here is a DEMO.
hh is for 12-hour clock from 01 to 12, HH is for 24-hour clock from 00 to 23.
For more information, check Custom Date and Time Format Strings
try this:
string strTime = "04/30/2013 23:00";
DateTime dtTime;
if(DateTime.TryParseExact(strTime, "MM/dd/yyyy HH:mm",
System.Globalization.CultureInfo.InvariantCulture,
System.Globalization.DateTimeStyles.None, out dtTime))
{
Console.WriteLine(dtTime);
}
This can also be the problem if your string is 6/15/2019. DateTime Parse expects it to be 06/15/2019.
So first split it by slash
var dateParts = "6/15/2019"
var month = dateParts[0].PadLeft(2, '0');
var day = dateParts[1].PadLeft(2, '0');
var year = dateParts[2]
var properFormat = month + "/" +day +"/" + year;
Now you can use DateTime.Parse(properFormat, "MM/dd/yyyy"). It is very strange but this is only thing working for me.
change the culture and try out like this might work for you
string[] formats= { "MM/dd/yyyy HH:mm" }
var dateTime = DateTime.ParseExact("04/30/2013 23:00",
formats, new CultureInfo("en-US"), DateTimeStyles.None);
Check for details : DateTime.ParseExact Method (String, String[], IFormatProvider, DateTimeStyles)
DateTime dt1 = DateTime.ParseExact([YourDate], "dd-MM-yyyy HH:mm:ss",
CultureInfo.InvariantCulture);
Note the use of HH (24-hour clock) rather than hh (12-hour clock), and the use of InvariantCulture because some cultures use separators other than slash.
For example, if the culture is de-DE, the format "dd/MM/yyyy" would expect period as a separator (31.01.2011).
Below code worked for me:
string _stDate = Convert.ToDateTime(DateTime.Today.AddMonths(-12)).ToString("MM/dd/yyyy");
String format ="MM/dd/yyyy";
IFormatProvider culture = new System.Globalization.CultureInfo("fr-FR", true);
DateTime _Startdate = DateTime.ParseExact(_stDate, format, culture);
You may use this type format (get formatted data from sql server)
FORMAT(convert(datetime,'16/04/2018 10:52:20',103),'dd/MM/yyyy HH:mm:ss', 'en-us')
CONVERT(VARCHAR,convert(datetime,'16/04/2018 10:52:20',103), 120)
I have the following date in string format "2011-29-01 12:00 am" . Now I am trying to convert that to datetime format with the following code:
DateTime.TryParse(dateTime, out dt);
But I am alwayws getting dt as {1/1/0001 12:00:00 AM} , Can you please tell me why ? and how can I convert that string to date.
EDIT: I just saw everybody mentioned to use format argument. I will mention now that I can't use the format parameter as I have some setting to select the custom dateformat what user wants, and based on that user is able to get the date in textbox in that format automatically via jQuery datepicker.
This should work based on your example "2011-29-01 12:00 am"
DateTime dt;
DateTime.TryParseExact(dateTime,
"yyyy-dd-MM hh:mm tt",
CultureInfo.InvariantCulture,
DateTimeStyles.None,
out dt);
You need to use the ParseExact method. This takes a string as its second argument that specifies the format the datetime is in, for example:
// Parse date and time with custom specifier.
dateString = "2011-29-01 12:00 am";
format = "yyyy-dd-MM h:mm tt";
try
{
result = DateTime.ParseExact(dateString, format, provider);
Console.WriteLine("{0} converts to {1}.", dateString, result.ToString());
}
catch (FormatException)
{
Console.WriteLine("{0} is not in the correct format.", dateString);
}
If the user can specify a format in the UI, then you need to translate that to a string you can pass into this method. You can do that by either allowing the user to enter the format string directly - though this means that the conversion is more likely to fail as they will enter an invalid format string - or having a combo box that presents them with the possible choices and you set up the format strings for these choices.
If it's likely that the input will be incorrect (user input for example) it would be better to use TryParseExact rather than use exceptions to handle the error case:
// Parse date and time with custom specifier.
dateString = "2011-29-01 12:00 am";
format = "yyyy-dd-MM h:mm tt";
DateTime result;
if (DateTime.TryParseExact(dateString, format, provider, DateTimeStyles.None, out result))
{
Console.WriteLine("{0} converts to {1}.", dateString, result.ToString());
}
else
{
Console.WriteLine("{0} is not in the correct format.", dateString);
}
A better alternative might be to not present the user with a choice of date formats, but use the overload that takes an array of formats:
// A list of possible American date formats - swap M and d for European formats
string[] formats= {"M/d/yyyy h:mm:ss tt", "M/d/yyyy h:mm tt",
"MM/dd/yyyy hh:mm:ss", "M/d/yyyy h:mm:ss",
"M/d/yyyy hh:mm tt", "M/d/yyyy hh tt",
"M/d/yyyy h:mm", "M/d/yyyy h:mm",
"MM/dd/yyyy hh:mm", "M/dd/yyyy hh:mm",
"MM/d/yyyy HH:mm:ss.ffffff" };
string dateString; // The string the date gets read into
try
{
dateValue = DateTime.ParseExact(dateString, formats,
new CultureInfo("en-US"),
DateTimeStyles.None);
Console.WriteLine("Converted '{0}' to {1}.", dateString, dateValue);
}
catch (FormatException)
{
Console.WriteLine("Unable to convert '{0}' to a date.", dateString);
}
If you read the possible formats out of a configuration file or database then you can add to these as you encounter all the different ways people want to enter dates.
The main drawback with this approach is that you will still have ambiguous dates. The formats are tried in order so no matter what it'll try the European format before the American (or vice versa) and cover anything where the day is less than 13 to a European formatted date even if the user thought they were entering an American formatted date.
Try using safe TryParseExact method
DateTime temp;
string date = "2011-29-01 12:00 am";
DateTime.TryParseExact(date, "yyyy-dd-MM hh:mm tt", CultureInfo.InvariantCulture, DateTimeStyles.None, out temp);
From DateTime on msdn:
Type: System.DateTime% When this method returns, contains the DateTime
value equivalent to the date and time contained in s, if the
conversion succeeded, or MinValue if the conversion failed. The
conversion fails if the s parameter is null, is an empty string (""),
or does not contain a valid string representation of a date and time.
This parameter is passed uninitialized.
Use parseexact with the format string "yyyy-dd-MM hh:mm tt" instead.
That works:
DateTime dt = DateTime.ParseExact("2011-29-01 12:00 am", "yyyy-dd-MM hh:mm tt", System.Globalization.CultureInfo.InvariantCulture);
DateTime dt = DateTime.ParseExact("11-22-2012 12:00 am", "MM-dd-yyyy hh:mm tt", System.Globalization.CultureInfo.InvariantCulture);
If you give the user the opportunity to change the date/time format, then you'll have to create a corresponding format string to use for parsing. If you know the possible date formats (i.e. the user has to select from a list), then this is much easier because you can create those format strings at compile time.
If you let the user do free-format design of the date/time format, then you'll have to create the corresponding DateTime format strings at runtime.