I need to know +/- mm:ss between 2 clocks

Occasional Visitor

I'm working on a timing display.

I have a start time for tv show 18:30:00

Then I have a duration for the show 00:28:000

On another sheet I have a rundown with a backtiming for instance 18:57:30
I need to know the difference between the backtimimg and starttime +/- mm:ss

2 Replies
There is an option in excel that can display negative time.
Go to excel options --> Advanced

Towards the end there is an option to use 1904 date system. Check it and you'll see negative time when subtrating.


Here are some links with information about it.

Subtract times

Calculate the difference between two times


...for more information

With your permission, please provide more information.

You'll get a quicker and more accurate answer, and those who want to help don't have to invest time guessing the problem.

What I recommend: Always inform about your Excel version, operating system, storage medium/hard drive, OneDrive, Sharepoint, etc.).

If possible, add a file (without sensitive data) and use this file to describe your project step by step, or add photos (as you have already done) with the appropriate description.

Don't forget that not every Excel user has a clue about every job and what you see he can't see.

In this link you will find some more information about it:

Welcome to your Excel discussion space!


Thank you for your understanding and patience



I know I don't know anything (Socrates)