Calculating Elapsed Time (simple question)

[Jarvis]

 I am trying to calculate how many minutes pass between when I start a task and when I complete it.

 

I have two timestamp fields:  start & stop.

They are populated with a script that inserts current time into each field upon clicking the start-stop button.

 

The calculation is as follows:

 

Case (  not IsEmpty ( Stop Time );(Stop Time - Start Time);"" )/60

 

This works fine as long as all of the hours occur within the same day.

As soon as the clock hits midnight, however,  the elapsed time becomes a negative value.

 

How should I express the formula?

[eos]

 As soon as the clock hits midnight, however,  the elapsed time becomes a negative value.

 

Not if you are really using timestamps.

 

And you can just write 

Case (  stop ; ( stop - start ) / 60 )

[comment]

have two timestamp fields

They are populated with a script that inserts current time into each field

 

 Make sure they are indeed timestamp fields, and let the script populate them with the current timestamp, not current time.

[Jarvis]

Thanks guys.  Problem solved.