If you're typing :37, excel will be seeing your entry as text.

Try typing 0:37.

To fix a bunch at once:
Select that range of cells.
edit|Replace
what: : (just the colon)
with: 0: (added zero)
replace all



G Man wrote:

I'm trying to track the average time a person uses a piece of equipment at
work. The average function does not seem to recognize time less than 1 hour
(i.e :37) in duration. I have about 30 occasions when the equipment was
used-- ranging from :05 to 3:10.

I appreciate your help.

--

Dave Peterson