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#ThrowBackThursday: Julian vs. Gregorian

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Q: Why is it that some history books say the Mayflower departed from England on September 6th, 1620, while others note that the date was September 16th?
A: Because the Pilgrims at the time were using the Julian Calendar (originally introduced by Julius Caesar in 46 BC) and according to it, they left on September 6. Edward Winslow documented the date in his famous journal (now known as Mourt’s Relation);”Wednesday the sixth of September, the wind coming east-northeast, a fine small gale, we loosed from Plymouth, having been kindly entertained and courteously used.”
However, we no longer use the Julian Calendar, and it’s about ten days behind our current calendar, the Gregorian Calendar, thus putting their departure date at September 16. The Julian calendar, was replaced because “it did not properly reflect the actual time it takes the Earth to circle once around the Sun, known as a tropical year or solar year.” The Gregorian calendar is just .002% days longer than the Julian calendar.
According to, “If you were living in England or one of the American colonies 260 years ago, the day September 13, 1752—didn’t exist. Neither did the 10 days preceding it. Instead, you would have gone to bed on the evening of September 2 and woken up on the morning of September 14. Eleven days had been effectively skipped over as part of the parliamentary measure that implemented the Gregorian calendar, aligning Britain and its overseas possessions with the rest of Western Europe.”
Here are a few other things you may not have known about the Gregorian Calendar:
The Gregorian Calendar is named after Pope Gregory XIII
Some of the last countries to convert to the Gregorian calendar were Russia (in 1918) and Greece (in 1923)
The main reason for creating and Gregorian Calendar was to change the date of Easter, which has fallen out of sync with the seasons
The Gregorian Calendar differs from the solar year by 26 seconds

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