Difference between times

I've been trying to get excel to calculate the difference between a start of duty time and and end of duty time.

It works ok for example if the duty starts at 07:00 and finishes at 19:00, however if the duty were to start at 19:00 and finish at 07:00 the following morning it comes up with #Value!

Does anyone know how to derive the difference between times if they are not on the same day?

Many thanks in advance.

Hi Daddylonglegs

Thanks for the prompt reply.

Tried your suggestion but the answer comes up as "FALSE"

Daddylonglegs.

Many appologies.

Had not set the format for the answer to display as a time.

Equation works now. Many thanks.