Scott says: > ...it seems intuitive that 12:00:01 am is one second after midnight, and 12:00:01 pm is one second after noon. By extension, it would be silly to consider 12:00:00 am as being offset by more than one second from 12:00:01 am. Someone else might say: > ...it seems intuitive that 11:59:59 am is one second before noon, and 11:59:59 pm is one second before midnight. By extension, it would be silly to consider 12:00:00 am as being offset by more than one second from 11:59:59 am. I'm not claiming one view is _more_ intuitive than the other: just highlighting that there's an "intuitive" view for both positions. And note in passing that the ambiguity is such that in 2008 the United States Government Printing Office _reversed_ their designations: before 2008 they had "12 a.m. = noon" and "12 p.m. = midnight" (matching the second "intuition") and from then switched designations (to match Scott's intuition).