Time and Dates

Hi,
How do i check to see if a user has entered the time in the format that i want it. I know about IsDate but is there anything for Time.
Suppose i want the time is a medium time format then how do i do this. I also want to check if the user has used the " : " separator in the time entered.
My second problem is how do i calculate the total time . Should i just minus the end time from the start time or is there something more to it.
Thanks for all the help in advance,
Derek

If Text1 Like "*:*" then
MsgBox "Correct"
else
MsgBox "Incorrect"
End If



Use that code to check if ":" present
And for second prblem, pleaase be more specific. Start and end time?