See here. Midnight has another problem: there is nothing to tell us "is this the beginning or ending of the day". Imagine your friends say they are leaving for holiday at "midnight" on 12th March, what day should you arrive to say goodbye? Do you get there on the 11th assuming they leave at the very start of the 12th , or the 12th assuming they leave at the end of the 12th? So, when you see something like "offer ends midnight October 15th" tell them to use one minute before or after so there is no confusion!
Midnight and Noon: AM or PM?
Converting AM/PM to 24 Hour Clock
Sign in Register. News Guardian. Nooks and crannies.
Two 12-Hour Periods
The hour clock is a time convention in which the 24 hours of the day are divided into two periods: a. The hour clock was developed from the middle of the second millennium BC to the 16th century AD. The hour time convention is common in several English-speaking nations and former British colonies, as well as a few other countries. The natural day-and-night division of a calendar day forms the fundamental basis as to why each day is split into two cycles. Originally there were two cycles: one cycle which could be tracked by the position of the Sun day , followed by one cycle which could be tracked by the Moon and stars night.