Which version of Excel are you using?

It should just work, but you will need to check the security settings, and when you load the sheet, you might need to look at the top, just below the ribbon/toolbar and enable content/macros...

In a cell, you should just need to enter =elapsed(start_date, end_date) and it will work. The start and end dates can be cell references.

The new module Module1 should be in the workbook you are using... I've tested it with 2010 and 2003 and it worked.

Edit: I've uploaded a copy of the sample code to my Dropbox account, you should be able to download it here:

http://dl.dropbox.com/u/7896028/timetest.xls

Dave - I love you!!

It works! It's brilliant! Thank you!

Don't tell my girlfriend!

Glad it works for you. It was actually fun developing that.

You have a twisted view of fun! But thanks, the relevant people were very happy, don't worry, I didn't steal the credit.

I've tucked that away for future use too.

Also, you helped with another problem, I'd completely forgotten about the script editor in Office and used it to unprotect a file which the user had gained from a departed staff member. Didn't know the password, removed the protection via script, magic!