datetime.parse in c#

Because this is not a valid format for the current culture. Please see all the System.DateTime.Parse, TryParse, ParseExact and TryParseExact methods:
http://msdn.microsoft.com/en-us/library/system.datetime.parse%28v=vs.110%29.aspx[^],
http://msdn.microsoft.com/en-us/library/system.datetime.tryparse%28v=vs.110%29.aspx[^],
http://msdn.microsoft.com/en-us/library/system.datetime.parseexact%28v=vs.110%29.aspx[^],
http://msdn.microsoft.com/en-us/library/system.datetime.tryparseexact%28v=vs.110%29.aspx[^].

You will find all the way to setup format options, either using format string or System.Globalization.CultureInfo (through System.IFormatProvider implemented by the class CultureInfo; you can also have a custom implementation of this interface). For string formats, please see:
http://msdn.microsoft.com/en-us/library/az4se3k1(v=vs.110).aspx[^],
http://msdn.microsoft.com/en-us/library/8kb3ddd4(v=vs.110).aspx[^].

See also:
http://msdn.microsoft.com/en-us/library/system.globalization.cultureinfo%28v=vs.110%29.aspx[^],
http://msdn.microsoft.com/en-us/library/system.iformatprovider%28v=vs.110%29.aspx[^],
http://msdn.microsoft.com/en-us/library/91hfhz89%28v=vs.110%29.aspx[^].

That's all. Get familiar with all that, and you will be able to parse DateTime any thinkable format.

—SA