excel stores time in number of days, to 8 hours is really 8/24, or 1/3. Use
this formula

=C2-8/24
or
=C2-1/3

Other notes about time:
-I like to keep it as 8/24, so it makes more sense to other people who might
look at it, but it really doesn't matter which format you use.
-If you want something in decimal hours (5.5 instead 5:30) mulitply the
result by 24 and format as a number.
-If you want elapsed time that will be over 24 hours use a custom number
format of
[h]:mm
without the brackets, 27:34 would show like 3:34.

"Stephanie" wrote:

This is time worksheet:

Time in/time out/Number hours/difference.

First three are fine. The difference should be the difference between
column C and 8 hours.

Ideally, it would show the difference in hours and minutes. I've tried
=C2-8, but all I get is #######.

Any suggestions?

--
Steph