using System;
using System.Globalization;

public class Test
{
	public static void Main()
	{
		string s = "6/6/2014 12:24:30 PM";
        DateTime dt;
        if(DateTime.TryParseExact(s, "M/d/yyyy hh:mm:ss tt",
                                  CultureInfo.InvariantCulture,
                                  DateTimeStyles.None, out dt))
        {
           Console.WriteLine(dt.ToString("yyyy-MM-ddThh:mm:ss.fffz"));
        }
	}
}