It is used to calculate hours worked. For example clocked in time is 13.11 and clocked out time is 22.08
Also, there are times like in @ 18:18 and out @ 6:23( considered 3rd shift)
1st, it;s very important the the cells containing your military times are in text format. if you just type them per your example, Excel automatically formats them as times, and this throws everything off.
If A2="18:18", and B2="6:23", then:
C2=VALUE(LEFT(A2,(FIND(":",A2)-1)))
.. gives you the clock-in hours
D2=IF(VALUE(LEFT(B2,(FIND(":",B2)-1)))<C2,VALUE(LEFT(B2,(FIND(":",B2)-1)))+24)
.. gives you clock-out hours. The IF statement adds 24 hours to this time if the hour is less than the clock-in hours.
E2=VALUE(RIGHT(A2,2))
.. gives you clock-in 1/100's of an hour
F2=VALUE(RIGHT(B2,2))
.. gives you clock-out 1/100's of an hour
G2=D2-C2+(F2-E2)/100
.. ties it all together, and gives you the hours worked. In this case, the answer would be 12.05
If you want one big formula, then just substitute the formula (for example, "VALUE(LEFT(A2,(FIND(":",A2)-1)))" for the address (in this case "C2") in the formula for G2.