12:59am subtract 1:00pm

[Bobby]

I have sheet like this
a1 1215
a2 1230
these numbers rep time, now when I subtract a1 from a2 i get the
correct 15
then this happens
a3 1259
a4 115
again I'm working with time since 115 is ahead of 1259, but not to
excel, and I understand this. Is there a way I can have excel tell me
the difference subtract 12:50 from 1:15?
My whole sheet works fine all 55 rows but it's when I go from 1259am
to 100pm is my problem.

Thanks Much

 

[Frank Kabel]

Hi
enter the values as Excel times. so
12:59
and
1:15

 

[Bobby]

Thanks Frank...