Well this was something is something from a program I wrote years back. Basically the user would put in a number and the program would then convert it to seconds and then begin the count down.

So to get this started, either drag a timer control over to your form or create one through code(not going to be going over this one)

Let's take what the use put in the textbox and convert it to seconds
(This program was based on hours)

Code:
 Private Sub btn_start_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_start.Click
  Dim time As String

time = txt_time.Text * 3600
txt_time.Text = time
timer1.enabled =true
 End Sub
I coded things wierd years ago, so you could pretty much do this a better way, but I'm just coping and pasting what I had.




In the timer_tick proceedure we are going to do this:

Code:
 Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
    
        txt_time.Text = myTime - 1
        myTime = txt_time.Text
        If txt_time.Text= 0 Then
           'Insert event here
            Next
        End If
    End Sub