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Console application string was not recognised as valid datetime

I have a excel sheet in which am taking a date column in this format "23/8/11 01:33:01:PM"
and am inserting it in sql 2008 using datarow but am getting a error
String was not recognised as valid datetime.
Can any one please help?
DateTime newdate = Convert.ToDateTime(row[8].ToString());

Here how Convert.ToDateTime method looks like when you decompile it;
public static DateTime ToDateTime(string value)
{
if (value == null)
return new DateTime(0L);
else
return DateTime.Parse(value, (IFormatProvider) CultureInfo.CurrentCulture);
}
As you can see, this method use DateTime.Parse method with your CurrentCulture. And if your string doesn't match your current culture date format, your code will be broken. That's the reason you get this error.
Use DateTime.ParseExact with "dd/M/yy hh:mm:ss:tt" format instead.
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.
string s = "23/8/11 01:33:01:PM";
DateTime newdate = DateTime.ParseExact(s, "dd/M/yy hh:mm:ss:tt", CultureInfo.InvariantCulture);
Console.WriteLine(newdate);
Output will be;
8/23/2011 1:33:01 PM
Here a DEMO.
For your case;
DateTime newdate = DateTime.ParseExact(row[8].ToString(), "dd/M/yy hh:mm:ss:tt", CultureInfo.InvariantCulture);
For more informations, take a look;
Custom Date and Time Format Strings

Convert.ToDateTime internally calls DateTime.Parse which by default will use the current culture of your application. If 23/8/11 01:33:01:PM is not a valid format for this culture then this method will fail.
For specific date formats it's best to use DateTime.ParseExact e.g.
DateTime.ParseExact("23/8/11 01:33:01:PM", "dd/M/yy hh:mm:ss:tt", CultureInfo.InvariantCulture);
This approach makes your code culture independent which means the date will always be parsed correctly (given it's in the specified format).

This will work:
DateTime newdate = Convert.ToDateTime("8/23/11 01:33:01 PM");
I changed day and month and removed the colon a the end. But that is very specific. You need to know more about the dates passed to do that.

C# Datetime format conversion

I have a conversion problem with datetime. I have a date string as MM/dd/yyyy. Now I need to convert it to yyyy-MM-dd.
But I'm facing some error. Please help
public static DateTime ToDBDateTime(string _dateTime)
{
string sysFormat = "MM/dd/yyyy hh:mm:ss tt";
string _convertedDate = string.Empty;
if (_dateTime != null || _dateTime != string.Empty)
{
_convertedDate = DateTime.ParseExact(_dateTime, sysFormat, System.Globalization.CultureInfo.InvariantCulture).ToString(_toDBDateFormat);
//_convertedDate = Convert.ToDateTime(_dateTime).ToString(_toDBDateFormat);
/// Debug.Print(sysFormat);
}
return Convert.ToDateTime(_convertedDate);
}
And I want to know that is there is any way to pass the datetime in various formats and it would return the expected format.
E.g.: if I pass date as dd/MM/yyyy or MM/dd/yyyy, the above function would return the date in format as yyyy-MM-dd.
Please provide some suggestion to solve datetime issues.

I have a date string as MM/dd/yyyy
Right... and yet you're trying to parse it like this:
string sysFormat = "MM/dd/yyyy hh:mm:ss tt";
...
_convertedDate = DateTime.ParseExact(_dateTime, sysFormat,
CultureInfo.InvariantCulture)
You need to give a format string which matches your input - so why are you including a time part? You probably just want:
string sysFormat = "MM/dd/yyyy";
However, that's not the end of the problems. You're then converting that DateTime back into a string like this:
.ToString(_toDBDateFormat)
... and parsing it once more:
return Convert.ToDateTime(_convertedDate);
Why on earth would you want to do that? You should avoid string conversions as far as possible. Aside from anything else, what's to say that _toDBDateFormat (a variable name which raises my suspicions to start with) and Convert.ToDateTime (which always uses the current culture for parsing) are going to be compatible?
You should:
Work out how you want to handle being given an empty string or null, and just return an appropriate DateTime then
Otherwise, just parse using the right format.
This part of your question also concerns me:
E.g.: if I pass date as dd/MM/yyyy or MM/dd/yyyy, the above function would return the date in format as yyyy-MM-dd.
There's no such thing as "the date in format as yyyy-MM-dd". A DateTime is just a date and time value. It has no intrinsic format. You specify how you want to format it when you format it. However, if you're using the value for a database query, you shouldn't be converting it into a string again anyway - you should be using parameterized SQL, and just providing it as a DateTime.

As you have a date in a string with the format "MM/dd/yyyy" and want to convert it to "yyyy-MM-dd" you could do like this:
DateTime dt = DateTime.ParseExact(dateString, "MM/dd/yyyy", CultureInfo.InvariantCulture);
dt.ToString("yyyy-MM-dd");

Use the inbuilt tostring like this:
Convert.ToDateTime(_convertedDate).ToString("MM/dd/yyyy") or whatever format you want.

I tried this and its working fine.
DateTime date1 = new DateTime(2009, 8, 1);
date1.ToString("yyyy-MM-dd hh:mm:ss tt");
You can apply any format in this ToString.
Hope that helps
Milind

Convert YYYYMMDD string to MM/DD/YYYY string

I have a date that is stored as a string in the format YYYYDDMM. I would like to display that value in a 'MM/DD/YYYY' format. I am programming in c#. The current code that I am using is as follows:
txtOC31.Text = dr["OC31"].ToString().Trim();
strOC31date = dr["OC31DATE"].ToString().Trim();
DateTime date31 = DateTime.Parse(strOC31date);
strOC31date = String.Format("{0:MM/dd/yyyy}", date31);
However, I am getting an error because the YYYYMMDD string (strOC31date) is not being recognized as a valid datetime.

DateTime.ParseExact with an example
string res = "20120708";
DateTime d = DateTime.ParseExact(res, "yyyyddMM", CultureInfo.InvariantCulture);
Console.WriteLine(d.ToString("MM/dd/yyyy"));

Use ParseExact() (MSDN) when the string you are trying to parse is not in one of the standard formats. This will allow you to parse a custom format and will be slightly more efficient (I compare them in a blog post here).
DateTime date31 = DateTime.ParseExact(strOC31date, "yyyyMMdd", null);
Passing null for the format provider will default to DateTimeFormatInfo.CurrentInfo and is safe, but you probably want the invariant culture instead:
DateTime date31 = DateTime.ParseExact(strOC31date, "yyyyMMdd", DateTimeFormatInfo.InvariantInfo);
Then your code will work.

Instead of DateTime.Parse(strOC31date); use DateTime.ParseExact() method, which takes format as one of the parameters.

You want the method DateTime.ParseExact.
DateTime date31 = DateTime.ParseExact(strOC31date, "yyyyddMM", CultureInfo.InvariantCulture);

splitting string to array to create dateTime in c#

I have a string called TheUserTime that looks like this:
string TheUserTime = "12.12.2011.16.22"; //16 is the hour in 24-hour format and 22 is the minutes
I want to generate a DateTime from this by splitting the string in a array of ints (what happens when it's 0?) and composing the date object.
What's the best way to do this?
Thanks.

You should use DateTime.ParseExact or DateTime.TryParseExact with a custom format string instead.
ParseExact:
DateTime.ParseExact("12.12.2011.16.22", "dd.MM.yyyy.HH.mm",
CultureInfo.InvariantCulture)
TryParseExact:
DateTime dt;
if(DateTime.TryParseExact("12.12.2011.16.22", "dd.MM.yyyy.HH.mm",
CultureInfo.InvariantCulture, DateTimeStyles.None,
out dt))
{
// parse successful use dt
}
Using TryParseExact avoids a possible exception if the parse fails, though is such a case the dt variable will have the default value for DateTime.

I would not recommend your approach, but instead use ParseExact and specify the expected format.
string theUserTime = "12.12.2011.16.22";
var date = DateTime.ParseExact(theUserTime, "MM.dd.yyyy.HH.mm", CultureInfo.CurrentCulture);

You can use:
DateTime.ParseExact("12.12.2011.16.22", "MM.dd.yyyy.HH.mm", System.Globalization.CultureInfo.InvariantCulture);

C# : Convert datetime from string with different format

If my string is 26/01/2011 00:14:00
but my computer set United state format (AM:PM)
How to convert my string into Datetime?
I try Convert.ToDateTime() but it cause error.

As the others have said, you can use DateTime.TryParseExact, but you also seem to have a European culture format in your date. It might not hurt to make an attempt to use that to perform the conversion:
CultureInfo enGB = new CultureInfo("en-GB");
string dateString;
DateTime dateValue;
// Parse date with no style flags.
dateString = "26/01/2011 00:14:00";
DateTime.TryParseExact(dateString, "g", enGB, DateTimeStyles.None, out dateValue);

Use DateTime.ParseExact or DateTime.TryParseExact. If you have to accept multiple possible datetime formats, both of those methods have overloads that take an array of format strings.
As far as that format, it looks like "dd/mm/yyyy HH:MM:ss"

I use DateTime.Tryparse - that way you can catch and handle a failure gracefully:
http://msdn.microsoft.com/en-us/library/system.datetime.tryparse.aspx