Neither works. The 1000 button changes the first digit ( x0:00 ) to either "1", "2", or not there. The 100 button changes the second digit ( 0x:00 ) to 0-9 if the first digit doesn't exist, 0-9 if the first digit is 1, 0-3 if the first digit is 2. The 10 button changes the third digit to whatever 0-5. ( 00:x0 ) And the 1 button changes the fourth ( 00:0x ).
Still stuck on military time here for now.