The dates 4/4, 6/6, 8/8, 10/10 and 12/12 always fall on the same weekday every year

[Kaleva]

https://www.timeanddate.com/date/doomsday-rule.html

In 2016, the above dates fell on a Monday.

In 2017, they fall on a Tuesday.

In 2018, they will fall on a Wednesday.

In 2019, they will fall on a Thursday.

And so on till 2022, when the dates will again fall on a Monday.

[unblock]

1. Cool! But not quite "and so on". In 2020 it will Saturday, not Friday, as it's a leap year.

[Xipe Totec]

2. Perhaps because all months except February have the same number of days?

So once a pattern is established, it will not change unless you change the calendar.

Like from Gregorian to Julian.

[pangaia]

3. They do?

[Xipe Totec]

4. From year to year, March has 31, April 30, and on and on.

Only February has a different number of days some years.

[pangaia]

5. Oh, my misunderstanding.apoligies,,

[Xipe Totec]

6. No worries; I can see now that my statement was ambiguous

Cheers!

[PoindexterOglethorpe]

7. Let's see. Thirty days has September,

April, June, and November. All the rest have thirty one save February. Can't recall the rest of the rhyme.

So how exactly do you figure that all the months except February have the same number of days? What have you missed all these years?

[secondwind]

8. All the rest have 31, except February which has 28, til leap year com s. Then it has one more

[Iggo]

10. I learned it....

Thirty days
Have September,
April, June,
And November.
All the rest
Have 31
Save February
Has 28.
But Leap Year,
That's the time
When February
Has 29."

I think it was a rough attempt at saving the meter. Or just that my sainted grandmother was straight from Ireland.

[Loyd]

9. Rome Robs February!

When they created July in honor of Julius Caesar, well, it had it have the max number of days, so they took one from February. This was repeated with Augustus and August.

I was born in February. Fuck Rome!

[a la izquierda]

11. I was burn in 8/8/77. Nt

[FSogol]

12. I hope your burns got better.

[a la izquierda]

13. Derp, posting sans coffee...

[FSogol]

14. LOL. n/t

[Thor_MN]

15. By necessity, that means 4/3, 6/5, 8/7, 10/9 and 12/11 are all on same weekday as well

And surprise, 4/6, 6/7, 8/9, 10/11 and 12/13 are as well...

Not really a mystery that dates that are a numbers of week apart happen to fall on the same day of the week. As long as you avoid January and February (because of leap years) this works for basically all sets of dates that are a number of weeks apart.

[Kaleva]

16. Thus there is a way to tell which any date falls on what weekday.

[left-of-center2012]

17. Why doesn't 'leap year' throw it off?

[KG]

18. coz those dates are after february