The calendar we use is a solar calendar, which is to say it is reckoned by the various positions of the sun with no regard to phases of the moon. A year is defined as the time between two successive crossings of the celestial equator.
Lunar calendars were based on the phases of the moon. Dividing a year into 12 lunar months totals just over 354 days, about 11 days short of a solar year. Ancient lunar calendars, such as the Hebrew calendar, added “leap months” to keep in step with the sun.
Just over 2,000 years ago, the new year began on the vernal equinox. In 45 BC, Julius Caesar made the calendar solar and moved the beginning of the year to January 1, when Roman consuls began their terms of office. A “leap day” was introduced every four years to keep the new calendar in sync.
Since the first century, the Roman calendar was divided into 12 months, with the same names for the months that we use today. But the system of ascribing a unique number to each year (2016, for example) didn’t come along until about 525 AD.
Before then, years were numbered according to the beginning of a ruler’s reign (e.g., 559 BC was the First Year of King Cyrus in Persia). However, each country had its own ruler and, therefore, counted the years differently. Each new place the Persians conquered had its own First Year of King Cyrus, each in a different year. Then some nations began the first year when the ruler came to power; others began the following year.
Almost 1,500 years ago, a monk by the name of Dionysius Exiguus simplified matters when he suggested the years be counted from the birth of Christ. All years prior to that would ascend into the past “before Christ,” and subsequent years ascend into the future, “anno Domini” (“the year of the Lord”). Therefore, 1 BC was followed by 1 AD.
However, historical data suggest the entire numbering system may be off by four to six years, in which case we’re not living in 2016, but in 2022!
This is because, under the Julian Calendar, there were three too many leap days every 385 years. By the time of Pope Gregory XIII in the 16th century, the solar calendar was off by 10 days, making it difficult to pinpoint religious holidays, such as Easter.
The Gregorian Calendar solved this by designating years exactly divisible by four as leap years, except for those exactly divisible by 100, but years ending in “00” are not leap years unless they are exactly divisible by 400. So, 1996, 2000, and 2004 were all leap years, but 1900 was not and 2100 won’t be either.
The Gregorian Calendar instantly eliminated those extra 10 leap days. As a result, Wednesday, October 4, 1582, was followed by Thursday, October 15, 1582. Roman Catholic countries quickly adopted this new system, but other nations were slower to do so.
England and its colonies continued to follow the Julian Calendar (including its practice of beginning the year on March 25) until 1752. This is why George Washington has two birthdays. He was born on February 11, 1731, under the old calendar, which is February 22, 1732, under the new calendar.
The French Republican Calendar was used from 1793 to 1806 following the French Revolution. It was comprised of 12 months of 30 days each, with five days tacked onto the end of the year (six in leap years). Weeks were replaced with “decades” of 10 days each.
But the Gregorian Calendar has held its own and is probably the most accurate calendar ever devised. One problem, however, is that a month can begin on any day of the week. The Thirteen-Month, or International Fixed Calendar would reduce the length of each month to exactly four weeks (February wouldn’t even notice).
The extra month, called Sol, would fall between June and July. Each 28-day month would begin on the same day of the week, totaling 364 days in a year. An extra “year day” would be placed at the end of the year, with a leap day every four years at the end of June (about time that extra day showed up during summer!).
Despite its advantages, the International Fixed Calendar is unlikely to take over. The business world functions on four quarters of three months each, and the transition to four 13-week quarters might be disruptive.
Leap days and year days would throw off the seven-day worship cycle of Jews, Christians, and Muslims. Major holidays, like Christmas and 4th of July, would fall permanently on a Wednesday, and every month would include a Friday the 13th.
Summer officially began this year on June 20 at 5:34 p.m. The beginning of the season calls for slightly sub-average temps and precipitation going into July. Then look for showers and thunderstorms.