Excel 24 hour clock using 100 minutes

Working for the Govt I have to cover 24 hour shifts that use a 100 minute clock. (i.e. 0715 is 0725 on 100 minute clock.) 2330 is 2350 on 100 minute clock. The problem I am having is night shift comes in at 2250 (1030pm) and get off work the next morning at 0750 (0730am). I have to convert the times manually then enter them into a spread sheet that tracks hours worked. Any idea how to count the time that goes from one day to the next. Any help would be greatly appreciated. I would like to be able to enter Begin Tour on Monday evening (BT=2250) in Col “A” Out to lunch (OL=0250) in Col “B” In from Lunch (IL=0300) in Col “C” and End of Tour on Tuesday Morning (ET=0700) in Col “D”. Then have Excel Put the total time worked in Col “E”