Question

I dont get following desired output from a DateTime-Object:

2010-03-29 13:15:00

My default localization is de-DE, so a simple ToString gives me:

29.03.2010 13:15:00

What I’ve tried is to create a DateTimeFormatInfo Object from US-Culture and use its DateTimePatterns but without success:

Dim usDateFormat As Globalization.DateTimeFormatInfo = New Globalization.CultureInfo("en-US", False).DateTimeFormat
usDateFormat.DateSeparator = "-"
ruleResult.Claim.Last_Updated_Date.ToString(usDateFormat.ShortDatePattern)

Output: 3.29.2010

What is the best way (readable,fastest) to get my desired DateTimeFormat(i need sometimes the short Date and sometimes the Date and Time like in my example above)?

Thanking you in anticipation,
Tim

EDIT: why does my DateTimeFormatInfo approach not work and makes it a performance difference when using the String.Format or ToString(“yyyy-MM-dd HH:mm:ss”) solutions instead of a private shared(static) DateTimeFormatInfo-Object? I’m calling this function at least 30k times and there are many Dates to format inside.

Answer 1

I think what you are looking for is:

DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");

Here are some examples, I think if look at then you can understand how it works:

// create date time 2008-03-09 16:05:07.123
DateTime dateTime = new DateTime(2008, 3, 9, 16, 5, 7, 123);

dateTime.ToString("y yy yyy yyyy");  // "8 08 008 2008"   year
dateTime.ToString("M MM MMM MMMM");  // "3 03 Mar March"  month
dateTime.ToString("d dd ddd dddd");  // "9 09 Sun Sunday" day
dateTime.ToString("h hh H HH"    );  // "4 04 16 16"      hour 12/24
dateTime.ToString("m mm"         );  // "5 05"            minute
dateTime.ToString("s ss"         );  // "7 07"            second
dateTime.ToString("f ff fff ffff");  // "1 12 123 1230"   sec.fraction
dateTime.ToString("F FF FFF FFFF");  // "1 12 123 123"    without zeroes
dateTime.ToString("t tt"         );  // "P PM"            A.M. or P.M.
dateTime.ToString("z zz zzz"     );  // "-6 -06 -06:00"   time zone