Thanks for the reply. When I changed the formula as you stated, I get 2:46 as a total. And yes, I did get 13, but, when I change B10 to 17:35, the formula doesn't work unless I edit reverse the "<" sign . . .
Also, how do I calculate the time when I start the next work assignment at 23:32 and end it the next day at 3:08 in the morning?