5 Weekends in 1 Month Happens More Often Than Every 823 Years
5 Fridays, 5 Saturdays, and 5 Sundays in a month? It happens only once every 823 years! This popular urban myth has been circulating the internet for a while. However, it is precisely that: a myth.
Don’t get too carried away with the excitement of this unique occurrence and start spreading the word to your loved ones. It’s important to note that claims that it only happens every 823 years are not accurate. The combination of 5 Fridays, 5 Saturdays, and 5 Sundays happens more frequently than that.
The 823 Years Myth
It’s likely that you’ve seen a viral post circulating on email or social media that claims a certain month will feature a rare combination of weekdays. The post encourages you to share it, warning that failing to do so could bring about bad luck.
A recent version goes something like this:
December 2023 has 5 Fridays, 5 Saturdays, and 5 Sundays. This happens only once every 823 years. The Chinese call it “silver pockets full” or “money bags.”
The email is partially correct. December 2023 does have 5 Fridays, 5 Saturdays, and 5 Sundays. But this is neither special nor unusual. You won’t need to wait for another 823 years for this weekday combination to occur. (In fact, it doesn’t even happen in the year 2846, which is 823 years after the year 2023!)
A calendar month that contains 5 Fridays, 5 Saturdays, and 5 Sundays actually occurs nearly every year—March 2024, August 2025, and May 2026 all have the same weekday pattern.
Recurring Monthly Calendars
Ready for some math? Here’s a more mathematical reasoning of why the 823-year claim is a myth:
Every year has 7 months with 31 days. Each of these months has at least 3 weekdays that happen 5 times during the month. For example, August 2023 has 5 Tuesdays, 5 Wednesdays, and 5 Thursdays. October 2023 has 5 Sundays, 5 Mondays, and 5 Tuesdays.
There are 7 different days a month can start. So, on average, the combination of any 3 days occurring 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 year, January and October have the same calendar, while January and July look the same in a leap year.
The Doomsday Rule for calendars
5-Day Combinations in a Month 2023
| Dates: | 1/ 8 / 15 / 22 / 29 | 2 / 9 / 16 / 23 / 30 | 3 / 10 / 17 / 24 / 31 | Comments |
|---|---|---|---|---|
| January 2023 | 5 Sundays | 5 Mondays | 5 Tuesdays | Same as October 2023* |
| March 2023 | 5 Wednesdays | 5 Thursdays | 5 Fridays | |
| May 2023 | 5 Mondays | 5 Tuesdays | 5 Wednesdays | |
| July 2023 | 5 Saturdays | 5 Sundays | 5 Mondays | |
| August 2023 | 5 Tuesdays | 5 Wednesdays | 5 Thursdays | |
| October 2023 | 5 Sundays | 5 Mondays | 5 Tuesdays | Same as January 2023* |
| December 2023 | 5 Fridays | 5 Saturdays | 5 Sundays | |
| January 2024 | 5 Mondays | 5 Tuesdays | 5 Wednesdays | Same as July 2024* |
| March 2024 | 5 Fridays | 5 Saturdays | 5 Sundays | |
| May 2024 | 5 Wednesdays | 5 Thursdays | 5 Fridays | |
| July 2024 | 5 Mondays | 5 Tuesdays | 5 Wednesdays | Same as January 2024* |
| August 2024 | 5 Thursdays | 5 Fridays | 5 Saturdays | |
| October 2024 | 5 Tuesdays | 5 Wednesdays | 5 Thursdays | |
| December 2024 | 5 Sundays | 5 Mondays | 5 Tuesdays |
* 2023 is a common year, 2024 is a leap year.
