The Enoch calendar is an ancient calendar described in the pseudepigraphal Book of Enoch. It divided the year into four seasons of exactly 13 weeks each. Each such season consisted of two 30-day months followed by one 31-day month, and the 31st Day ended the Season. Enoch's Year consisted of exactly 364 days and the day had 18 parts per day of 80 minutes per part, which is equal to today's 24 hours per day and 60 minutes per hour, both totaling 1440 minutes per day. In order to create the 365 Day in the Julian and Gregorian Calendars, the 24 hour day was reduced to 23 hours, 56 minutes and 5 seconds, a Sidereal Day.