Generally you would add a Timer to your form and set its Interval to 1000 (milliseconds). You would then handle the Tick event of the Timer to update your Label so it always shows the current time:
VB Code:
  1. '24 hour time, no seconds.
  2.         Me.Label1.Text = Date.Now.ToString("HH:mm") 'Note that the "mm" is lower case because upper case means month.
  3.  
  4.         'Standard time format.
  5.         Me.Label1.Text = Date.Now.ToShortTimeString()
  6.  
  7.         'GMT.
  8.         Me.Label1.Text = Date.Now.ToUniversalTime().ToShortTimeString()