Time validation C#

using System.Text.RegularExpressions;

string strcd = DateTime.Now.ToString("hh:mm:ss tt"); //02:56:59 PM 

bool isOK = Regex.IsMatch(strcd, @"[0-2][0-9]\:[0-5][0-9]\:[0-5][0-9]\ [aApP][mM]");

if (isOK)

  {

     // Do something.

  }

else

  {

string strcd = DateTime.Now.ToString("hh:mm tt"); //01:06 PM        

bool isOK = Regex.IsMatch(strcd, @"[0-2][0-9]\:[0-5][0-9]\ [aApP][mM]");

if (isOK)

  {

     // Do something.

  }

else

  {

     // Do something else.

  }