That's kind of normal isn't it ?
It goes from
00 hours 00 minutes 00 seconds -> 11 hours 59 minutes 59 seconds
The next seconds it all begins at 00 (I can be mistaken of course)
ok then, if you owned a store and were going to hang your hours in the window... lets say sunday you wanted to open at noon but you had to choose a 2 digit number for your opening time... 00 or 12