Convert datetime without timezone

you can try this.

DateTimeOffset.Parse("2013-07-22T08:51:38.000-07:00").DateTime.ToString("dd-MM-yyyy hh:mm:ss tt");

You can try the below one

        string s = "2013-07-22T08:51:38.000-07:00";

        DateTime d = Convert.ToDateTime(s);

        Console.WriteLine(d.Date.ToShortDateString());

You can use the DateTime property of DateTimeOffset.

Example:

string s = "2013-07-22T08:51:38.000-07:00";
var dateTimeOffset =DateTimeOffset.Parse(s, null);
Console.WriteLine(dateTimeOffset.DateTime); 

Outputs:

22/07/2013 08:51:38