Human evolution has been effected by calendars, and the calendars we use have changed throughout history. Classical writers like Aristotle, Apollonius of Rhodes, and others recorded traditions of a Greek tribe, the Arcadians, who claimed to have lived in the land “before the moon was in the sky.” This concept is sometimes called Proselenos, which translates to “those who were before the Moon.” If this was the case, timekeeping could have been tracked through the migration of animals, cycles of vegetation, and local weather patterns.
Calendars dating back ten thousand years were attuned to the cycles of the moon. A true lunar month lasts about 29.5 days. Twelve of these cycles equal 354 days. Ancient civilizations on this calendar would add an extra 13th month every few years whenever they noticed the seasonal drift, a process called intercalation. Later on they moved to the Metonic cycle, where 7 extra months are added every 19 years. The Hebrew Calendar still uses this cycle today.
Romulus, the mythical first king and founder of Rome, is said to have instituted the 10-month solar calendar. September, October, November, and December derive from the Latin words for seven, eight, nine, and ten. The rest of the months have been renamed after gods, rituals, and in two cases, emperors. July was originally Quintilis, the 5th month, but was renamed to honor Julius Caesar. August was originally Sextilis, the 6th month, and was renamed to honor Rome’s emperor, Augustus Caesar. The 10 month year began at the vernal equinox in March, and ended in December, at which point the calendar ended. The remaining 61 days of winter were treated as a nameless void, until the vernal equinox was observed and the calendar reset. Around 713 BC, Romulus’s successor Pompilius instituted Januarius and Februarius to account for the winter.
In his book, Worlds in Collision, Immanuel Velikovsky reveals that almost every ancient civilization used a 360-day calendar. He claimed that a cataclysm around the 8th century BC changed the year from 360 days to 365.25 days. Velikovsky tied this to the Biblical event in 2 Kings 20 and Isaiah 38, where King Hezekiah is granted a miracle, and the shadow on the sundial of Ahaz moves backward by 10 degrees.
The Julian Calendar was launched in 45 BC to fix the old corrupted system instituted by Romulus and Pompilius, which was governed by politicians and priests who routinely added or subtracted days to extend their terms in office, delay elections, or alter tax deadlines. Inspired by Egyptian astronomers in Alexandria, the Julian Calendar is a 365.25-day solar calendar with a leap year added every four years.
On October 15, 1582, the Gregorian calendar was launched as today’s system. It was introduced by Pope Gregory XIII to correct the inaccuracies of the Julian calendar, which by 1582 was 10 days out of sync with the actual sun. The new Gregorian calendar system established that leap years occur every 4 years, except for years ending in “00”, which must be divisible by 400 in order to be a leap year. 10 days were then erased from history, and October 4, 1582 was immediately followed by October 15, 1582. Because of this change, the Gregorian calendar is accurate to within 26 seconds of the solar year, and it takes roughly 3,300 years for it to drift by a single day.
When Pope Gregory changed the calendar in 1582, Protestant and Eastern Orthodox countries viewed the correction as a Catholic conspiracy. For centuries, crossing a border in Europe meant traveling 10 to 13 days backward or forward in time. The Eastern Orthodox Church use a revised Julian calendar today.
If you divide the solar year by the average lunar cycle of 28 days, you get 13 months with one leftover day, or two in leap years. In this system, every month starts on a Sunday and ends on a Saturday. And the extra day is celebrated as a holiday. While never adopted by dominant empires, this 13-month calendar was proposed in 1849 as the Positivist Calendar, and in 1902 as the International Fixed Calendar. This calendar was so efficient that George Eastman used it at the Eastman Kodak Company, where it was used internally from 1928 to 1989.
