The timer object is used to perform a task at an specified time interval.

Example:
If you set the timer to an interval of 1000 then the timer event (OnTimer) will be executed every second. If you set it to 60000 then the timer will be executed every minute and so on...

I have used this to show timed dialog boxes to the user. When the timer is trigged the dialog boxe wil close just like the timeout value on the MessageBox() function.

Here is how i used it in my code:

code:
$tmrTimer          = $Form.Timer()
$tmrTimer.InterVal = 20000 ;20 seconds / time is given in milliseconds
$tmrTimer.OnTimer  = "tmrTimer_OnTimer()"

Function tmrTimer_OnTimer()
  $Form.Hide
EndFunction
I hope this explains some of it..