My 6 six year old son just explained to me that George Washington's birthday is actually February 11

[Zuiderelle]

and not February 22, according to the Julian Calendar in effect when he was born. 20 years later in 1752 Britain adopted the Gregorian calendar and removed 11 days, so Washington and everyone since then has recognized his actual birthday as February 22nd.

There is often a difference of 11 to 13 days between the date an event occurred in history and the date it is celebrated on the calendar today. This is due to a discrepancy that occurred in the shift from the Julian to the Gregorian Calendar.

The Julian Calendar, named for Julius Caesar, called for an extra day (Leap Day) to be inserted once every four years, in order to keep consistent with the 365 & 1/4 day solar year.

It was a vast improvement over the previous Roman calendar, which drifted up to 100 days from the actual solar year. However even the Julian calendar wasn’t entirely accurate. The solar year is slightly less than 365 & 1/4 days. Not enough to notice at first. It took almost a century for the Julian Calendar to drift just one day from the solar year.

But by the 1500s people were starting to notice that the calendar was off by 11 days from the summer and winter solstice.

Astronomers calculated that to accurately mirror the solar year, one Leap Day had to be removed each century. In other words, each century should have 24 Leap Years rather than 25. The new calendar was called the Gregorian calendar, because it was installed under Pope Gregory’s Papacy in 1582 AD. (This is why years ending in '00 no longer have Leap Days. (Except every 400 years which is why 2000 was a Leap Year. {Just don't worry about it. You have better things to do with your brain power. Why are you even reading this?})

Anyway to get rid of the 11 excess days that had accumulated over the previous 15 centuries Pope Gregory did just that. He tossed 11 days from the 1582 calendar. This means people went to bed on October 4th, 1582 and woke up on October 15th.

How did I not know this? I knew we switched at some point from the Julian to the Gregorian calendar, but losing 11 days? Not a clue. The things you learn from a six year old.

http://everydaysaholiday.wordpress.com/date-me/

[XemaSab]

1. That's the second time today I have heard about the different dates of birth

First time was when I looked up Nabokov. :D

Good to know. :patriot:

[Kutjara]

2. Fascinating. One tiny question, though:

Since Britain didn't adopt the Gregorian Calendar until 1752, nearly 200 years after the rest of Europe, the gap between the two calendars would have widened by another two days, wouldn't it? That presumably explains the line in the article about calendars being "between 11 and 13 days" off. So, shouldn't we therefore celebrate Washington's birthday on the 24th?

Pedantic minds want to know.

[KamaAina]

3. Or, the present-day Washington's Birthday should really be on the 24th.

So, wouldn't George Washington then "really" have been born on the 9th?

Hey, maybe that would create enough space between it and Lincoln's Birthday (indisputably the 12th) that we could go back to getting both off instead of having to settle for the mashup known as "Presidents' Day"!

[Kutjara]

4. LOL. I actually edited my post to say the same thing.

It occurred to my brilliant mind that maybe Washington actually knew the day he was born, so it was much more likely that the shift due to the calendar change was wrong, rather than that the Father of Our Country didn't know his own birthday. You can see why I get the big bucks. Doh!

[Zuiderelle]

5. Good question.

Now I have a headache.