Logically, 1:00 A.M. is 1 hour before noon, or 11:00 on a 24-hour clock. Since we don't count backwards on the clock face, A.M/P.M. designates which cycle on a 12-hour clock we are in. 12:00:01 A.M. is 1 second after midnight.
Logically, 1:00 A.M. is 1 hour before noon, or 11:00 on a 24-hour clock. Since we don't count backwards on the clock face, A.M/P.M. designates which cycle on a 12-hour clock we are in. 12:00:01 A.M. is 1 second after midnight.