How do I process hours greater than 24

[dixr]

Doing a timesheet application, how to I add up the hours when they exceed 24
hours? The same issue would come up in a project management application when
the project will exceed 24 hours. I need to have hours up to thousands. The
applications need to keep fractional hours in minutes - hhhh:mm

 

[Fred Smith]

Use a format like:
[h]:mm

Regards,
Fred

 

[Gary''s Student]

Format the cells as [hhhhhh]:mm:ss