Calculation with timetable

Good evening I would like your help for a formula that verifies if adding a certain time to another is over or less than 24 hours
Example: in the attached file in B9 I 01.00
if I add 06.00 (E2) we arrive at 07.00
therefore less than 24.00 but the formula in F9 says true.
While if I use 23,59,59 in G9 says false which is the right result.

So I have to use 23,59,59 or another way to put 24?
Thank you