Quote Originally Posted by Loagina View Post
What the heck is 00:00 PDT? I know what 23:00 is but I had to look it up. Why the military all of a sudden?
https://en.wikipedia.org/wiki/Midnight
Midnight marks the beginning and ending of each day in civil time throughout the world. As the dividing point between one day and another, midnight defies easy classification as either part of the preceding day or of the following day. Though there is no global unanimity on the issue, most often midnight is considered the start of a new day and is associated with the hour 00:00. Even in locales with this technical resolution, however, vernacular references to midnight as the end of any given day may be common.

The US National Institute of Standards and Technology (NIST) recommends avoiding confusion altogether by using "00.01 am" and the date instead of "midnight".

Use of a 24-hour clock can remove ambiguity. The "midnight" term can be avoided altogether if the end of day is noted as 24:00 and the beginning of day as 00:00. While both notations refer to the same moment in time, the choice of notation allows its association with the previous night or with the following morning.
Too many people confuse midnight with the wrong day. 00:00 is unambiguous.

"Midnight Tuesday" is sometimes seen as the beginning of Tuesday or the end of Tuesday. Using 00:00 makes it absolutely clear if you say 00:00 PDT Tuesday, you mean the beginning of Tuesday.