Calculating Time Elapsed

Hello Excel folks,

I have data with a column in date format containing the START date & time of a task.
I also have a column containing the FINISH date & time of this same task.

I would like to calculate the time elapsed to complete the task.

The data in one of the Start time cells looks like this:
09-Apr-2010 08:44:10

And in another cell, the FINISH time looks like this:
09-Apr-2010 08:51:22

The format of these cells is DATE.

Is there a way to calculate the time elapsed with this type of data?

Your help is much appreciated!

Al.

Thank you. That helps a bunch.
I did try that originally, but the returned info made no sense. I think it was the formatting.


Next question, I want to do an IF statement looking for values higher than 15 minutes.
So, for cell D1 I will enter a formula.

=If(C1>00:15:00,1,0)

This does not work.

How can I check for times more than 15 minutes???