1881, John Harvey Kellogg, Plain Facts for Old and Young: Among most modern nations, the civil laws fixing the earliest date of marriage seem to have been made without any reference to physiology, or with the mistaken notion that puberty and nubility are identical.
Hours. Verizon defines the times that fit within the unlimited nights and weekends plan. Unlimited night calling time begins at 9:01 p.m. and ends at 5:59 the next morning. These hours apply weekdays, Monday through Friday.
Dark Thirty means anytime very early in the morning. Generally Zero Dark Thirty is used as a slang term by anyone that has a very early morning duty between the hours of 00:00 and 04:00 (Midnight to 4 am). So since most answers are wrong and the ones that are right got down voted I will clarify.