|
|
david12345 Special user 714 Posts |
Hey guys just read this today.
This year, July has 5 Fridays, 5 Saturdays and 5 Sundays. This happens once every 823 years. |
mastermindreader 1949 - 2017 Seattle, WA 12586 Posts |
Interesting and cool. But, actually, calendars repeat themselves every twenty years.
|
Tom Cutts Staff Northern CA 5925 Posts |
|
Scott Cram Inner circle 2678 Posts |
Quote:
On 2011-02-10 00:16, mastermindreader wrote: Actually, calendars only repeat themselves exactly every 400 years, not every 20 years. For example, March 1st, 2080, falls on a Friday. However, jump 20 years later to March 1st, 2100, and March 1st falls on a Monday! Barring an unexpected changes in our current calendar format, however, I can guarantee you without looking that 400 years from today, February 9, 2411, will fall on a Wednesday, just as it did this year. If it weren't for the fact that years ending in "00" are only leap years if they're divisible by 400 (which is also part of the reasoning behind the 400-year rule), the 20-year rule might work 100% of the time, instead of just frequently. Quote:
On 2011-02-09 22:49, david12345 wrote: Obviously, if a calendar repeats exactly every 400 years, this isn't true. Another way of saying that a particular month has 5 Fridays, 5 Saturdays and 5 Sundays, is to say that a 31-day month starts on a Friday. Do you really believe that 31-day months start on Friday only every 823 years? Guess what? After July 2011, the following months will also have 5 Fridays, 5 Saturdays and 5 Sundays: March 2013 August 2014 May 2015 January 2016 July 2016 See that? It happens twice in 2016! Seems like the average of that particular happening is more like once or twice a year. I've also seen the same e-mail going around using the wording "5 Sundays, 5 Mondays, and 5 Tuesdays", and other assorted day sequences, depending on the month given in the e-mail. |
mastermindreader 1949 - 2017 Seattle, WA 12586 Posts |
Actually I was wrong with the 20 years. I should have said 28 for the general rule, but I see where you get the 400.
http://askville.amazon.com/years-calenda......15689612 Am still wondering how anyone could possibly have come up with 823. Good thoughts, Bob |
david12345 Special user 714 Posts |
Now I have some research to do. I hate bad information. It sounded too strange to be made up.
|
stanalger Special user St. Louis, MO 998 Posts |
Quote:
On 2011-02-10 02:11, Scott Cram wrote: Frequently? Never! |
mastermindreader 1949 - 2017 Seattle, WA 12586 Posts |
28 year repeats are indeed extremely frequent. See the link I provided above.
|
stanalger Special user St. Louis, MO 998 Posts |
Dr. Bob,
Yes, 28-year repeats are extremely frequent. But 20-year repeats never occur within the Gregorian system. (You corrected your 20/28 error/typo. I'm just surprised that Scott didn't catch it.) |
The Magic Cafe Forum Index » » Penny for your thoughts » » More calendar phenomenon this year (0 Likes) |
[ Top of Page ] |
All content & postings Copyright © 2001-2024 Steve Brooks. All Rights Reserved. This page was created in 0.03 seconds requiring 5 database queries. |
The views and comments expressed on The Magic Café are not necessarily those of The Magic Café, Steve Brooks, or Steve Brooks Magic. > Privacy Statement < |