Posted on 02/29/2024 11:35:33 AM PST by DallasBiff
Nearly every four years, we add an extra day to the calendar in the form of February 29, also known as Leap Day. Put simply, these additional 24 hours are built into the calendar to ensure that it stays in line with the Earth’s movement around the sun.
While the modern calendar contains 365 days, the actual time it takes for Earth to orbit its star is slightly longer—roughly 365.2421 days. The difference might seem negligible, but over decades and centuries that missing quarter of a day per year can add up. To ensure consistency with the true astronomical year, it is necessary to periodically add in an extra day to make up the lost time and get the calendar back in synch with the heavens.
(Excerpt) Read more at history.com ...
I believe Centuries are the exception and Millenia are the exception to the exception.
Because the earth’s rotational period is not exactly .250000 “off each year.
That .242 bit requires we “subtract” (well, not add a Leap Day) every 1000 years.
True.
No, the .242198 means we don’t add a 29th of Feb on the century mark, except for each fourth one. That’s why we got a regular leap year in 2000, and most people alive at that time never saw the skip of one in 1900. Most people alive in 2000 won’t see the skip of one in 2100.
https://dfns.dyalog.com/n_Gregorian_calendar.htm
and also:
https://freerepublic.com/focus/chat/1203912/posts
Now that I’m much older, I can think of Leap Day as “Step Over Gently Day”.
If the Julian calendar "slipped" exactly a day every century, we could just skip leap day every century year and be done with it. However, it "slips" a little bit less than that, so we only skip 3 out of every 4 century years.
Addendum: depending on where you look, some calendars might tell you that 1700 was a leap year. That’s because the UK and her colonies, etc., didn’t switch to the Gregorian calendar until 1752. On the Gregorian calendar, 1700 was not a leap year.
Thank you. Oopsie.
I wonder how Islam corrects its calendar over time. I know the Christian (western) calendar had to be updated because Easter was explicitly linked to the yearly Passover celebration, and the western calendar had slipped intolerably from the expected date by the Medieval period.
Islam calendar never corrects. It’s Lunar based.
That’s why Ramadan comes in different months every year..................
No, it’s the rules. Because the mismatch in our flight around the sun is odd. So leap years are:
Every year divisible by 4
Except years divisible by 100
Except except years divisible by 400
So 1900 wasn’t a leap year. 2000 was. 2100 won’t be. 2400 will be.
Last night I discussed with my husband, and he said there were probably more rules about leap years than the basic every 4. I’m glad you know the rules.
It was a big deal in the world of software in 99. Y2K wasn’t just about the first 2 digits. And there was some alpha nerd going on about all this.
Then of course there’s the occasional leap second that nobody is really sure when they happen, except when we’re told to.
There is no Islamic correction for seasons.
The Hebrew calendar is limited because Passover is supposed to be in spring season, but the months are based on new moons. There is no requirement of the number of months in a solar year, so the Hebrew calendar has ‘leap months’, as is the case this year with two months named ‘Adar’ leading up to Passover.
My dad was a prepper back then, you know, just in case. Plus it was his and Mama’s 50th anniversary, so we had a BIG BASH!! Helluva celebration we had that night, that went on well until near daylight. I guess about 4 am it fizzled out. Now that I think about it, that was the after party, cuz the venue where we had the celebration closed by 9 pm. We had rented it out for most of the afternoon and evening. Lotsa fun and I remember there were so many people who knew my parents over that many years. Good times!
As with other tidbits in Islam, its lunar calendar is derived from the Jewish calendar.
Besides, why should Islam even *need* correction? /sarc
Good copy! I knew this stuff better twenty five years ago before my head was cluttered with tens of thousands of acronyms.
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