Useful tips for handling DateTime and String

Convert String to DateTime

1. User CultureInfo class to parse the DateTime string

CultureInfo cultEnUs = new CultureInfo("en-US"); DateTime myDate = Convert.ToDateTime("03/22/2010", cultEnUs.DateTimeFormat);

2. User the DateTimeFormatInfo class to parse the DateTime string

string strDate = "21-07-2006"; DateTimeFormatInfo dtfi = new DateTimeFormatInfo(); dtfi.ShortDatePattern = "dd-MM-yyyy"; dtfi.DateSeparator = "-"; DateTime objDate = Convert.ToDateTime(strDate, dtfi);

Convert DateTime to String

1. Use the DateTime.ToString Method. This is the easiest way to convert DateTime to a string.

Example:

DateTime.Now.ToString("yyyy-MM-dd");

2. User the String.Format Method.

There are following custom format specifies y (year), M (month), d (day), h (hour 12), H (hour 24), m (minute), s (second), f (second fraction), F (second fraction, trailing zeroes are trimmed), t (P.M or A.M) and z (time zone).

Following examples demonstrate how are the format specifies rewritten to the output.

// create date time 2008-03-09 16:05:07.123

DateTime dt = new DateTime(2008, 3, 9, 16, 5, 7, 123);

You can use also date separator / (slash) and time Separator : (colon). These characters will be rewritten to characters defined in the current DateTimeFormatInfo.DateSeparator and DateTimeFormatInfo.TimeSeparator.

// date separator in german culture is "." (so "/" changes to ".")

String.Format("{0:d/M/yyyy HH:mm:ss}", dt); // "9/3/2008 16:05:07" - English (en-US) String.Format("{0:d/M/yyyy HH:mm:ss}", dt); // "9.3.2008 16:05:07" - German (de-DE)

Here are some examples of custom date and time formatting:

// month/day numbers without/with leading zeroes String.Format("{0:M/d/yyyy}", dt);            // "3/9/2008" String.Format("{0:MM/dd/yyyy}", dt);          // "03/09/2008"

// day/month names String.Format("{0:ddd, MMM d, yyyy}", dt);    // "Sun, Mar 9, 2008" String.Format("{0:dddd, MMMM d, yyyy}", dt);  // "Sunday, March 9, 2008"

// two/four digit year String.Format("{0:MM/dd/yy}", dt);            // "03/09/08" String.Format("{0:MM/dd/yyyy}", dt);          // "03/09/2008"

Standard DateTime Formatting

In DateTimeFormatInfo there are defined standard patterns for the current culture. For example property ShortTimePattern is string that contains value h:mm tt for en-US culture and value HH:mm for de-DE culture.

Here are patterns defined in DateTimeFormatInfo and their values for en-US culture. First column contains format specifies for the String.Format method. (*) = culture independent

Following examples show usage of standard format specifiers in String.Format method and the resulting output.