Home > Calendar > Why 5 Fridays, 5 Saturdays & 5 Sundays don’t only occur every 823 years

Why 5 Fridays, 5 Saturdays & 5 Sundays don’t only occur every 823 years

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If you own an email, Twitter, Facebook or any other social media account, chances are that you have come across an email or a post that claims that an upcoming month has a very rare specific combination of days - usually, 5 Fridays, 5 Saturdays and 5 Sundays. Such emails go on to claim that such a combination is so rare that it will not happen for the next 823 years.

Before you get excited about this once-in-a-lifetime event and start telling your family and friends, know this: any such claims are false. Special combinations of days like 5 Fridays, 5 Saturdays and 5 Sundays occur much more often than every 823 years!

Busting the 823 year myth

Every few months, a version of this rumor surfaces on the internet. A recent version goes something like this:

August will have 5 Fridays, 5 Saturdays and 5 Sundays. This happens only once every 823 years. The Chinese call it silver pockets full.

The email is right in that August 2014 has 5 Fridays, 5 Saturdays, and 5 Sundays. But this is nothing special or unusual. You will not have to wait another 823 years for the next time this happens in August. Only 11 years from now in 2025, August will have 5 Fridays, 5 Saturdays, and 5 Sundays.

In fact, a calendar month that contains 5 Fridays, 5 Saturdays and 5 Sundays occurs nearly every year - May 2015 will have 5 Fridays, 5 Saturdays and 5 Sundays.

In fact, the calendar 823 years in the future is not even the same as the calendar of the month in the many versions of the hoax! For instance, August 2014 has 5 Fridays, 5 Saturdays and 5 Sundays. 823 years later, August 2837 has 5 Saturdays, 5 Sundays and 5 Mondays.

Variations of the myth:

  • This year July has 5 Fridays 5 Saturdays and 5 Sundays. This happens once every 823 years. This is called money bags.
  • This year, July has 5 Fridays, 5 Saturdays and 5 Sundays. This happens only once every 823 years.
  • This year October will have 5 Sundays, 5 Mondays and 5 Saturdays. This happens only every 823 years.
  • 2014: August has 5 Sundays, 5 Mondays and 5 Saturdays which only happens every 823 year
  • August 2014 has 5 Fridays, 5 Saturdays and 5 Sundays. Only happens every 823 years…

Not a special combination of days

The combinations of days that these messages or emails refer to are also not very special. This is because the first three weekdays of any 31-day month are repeated 5 times within that month. So, any month that has 31 days and begins on a Friday will have 5 Fridays, 5 Saturdays, and 5 Sundays. Similarly, any 31-day month that begins on a Tuesday, will have 5 Tuesdays, 5 Wednesdays and 5 Thursdays.

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Proof in cold print: 823 years from now, August 2837 will not
have 5 Fridays like August 2014

Take a look at our calendars and take it to the test!

Recurring monthly calendars

Here's a more mathematical reasoning as to why the 823 year claim is a myth:

Every year has 7 months with 31 days. Each of these months have at least 3 weekdays that happen 5 times during the month. For example, August 2014 has 5 Fridays, 5 Saturdays and 5 Sundays. October 2014 has 5 Wednesdays, 5 Thursdays and 5 Fridays.

There are 7 different days a month can start on. So on average, the combination of any 3 days occuring 5 times in a calendar month will happen once a year.

In any given year, there are only 6 such combinations of days. This is because 2 months with 31 days start on the same weekday. In a common or regular year, January and October have the same calendar, while in a leap year, January and July look the same.

2014: 5 weekday combinations in a month

Days that occur 5 times, on these dates:
1 / 8 / 15 / 222 / 9 / 16 / 233 / 10 / 17 / 24
31 day month29th of month30th of month31st of monthComments
January 20145 Wednesdays5 Thursdays5 FridaysSame as October
March 20145 Saturdays5 Sundays5 Mondays
May 20145 Thursdays5 Fridays5 Saturdays
July 20145 Tuesdays5 Wednesdays5 Thursdays
August 20145 Fridays5 Saturdays5 Sundays
October 20145 Wednesdays5 Thursdays5 FridaysSame as January
December 20145 Mondays5 Tuesdays5 Wednesdays
Not occurring in 2014: A month with 5 Sundays, 5 Mondays, 5 Tuesdays

2015: 5 weekday combinations in a month

Days that occur 5 times, on these dates:
1 / 8 / 15 / 222 / 9 / 16 / 233 / 10 / 17 / 24
31 day month29th of month30th of month31st of monthComments
January 20155 Thursdays5 Fridays5 SaturdaysSame as October
March 20155 Sundays5 Mondays5 Tuesdays
May 20155 Fridays5 Saturdays5 Sundays
July 20155 Wednesdays5 Thursdays5 Fridays
August 20155 Saturdays5 Sundays5 Mondays
October 20155 Thursdays5 Fridays5 SaturdaysSame as January
December 20155 Tuesdays5 Wednesdays5 Thursdays
Not occurring in 2015: A month with 5 Mondays, 5 Tuesdays, 5 Wednesdays

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