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What day is it on that date?
Not long ago, I fell into a rabbit hole on YouTube and found myself watching a video on how to determine what day of the week a particular date fell on. For example, you might hear November 22, 1963, and this technique helps you to quickly determine that it was a Friday.
For things like that, it’s admittedly of relatively little value. However, looking at just the current year it is much easier and likely more helpful.
What astonished me is learning how many days in any given year share the same day of the week. The idea is to remember those days, and what day of the week they represent, and it’s pretty easy to count from there. Some people call these “doomsdays” and others call them “pi day” (because March 14 is one of them).
The list starts like this, with these days all falling on the same day of the week:
- 4/4, 6/6, 8/8, 10/10 and 12/12. That worked out great!
- Next, imagine that you need to work 9–5 at 7/11. Well, we also get 9/5, 5/9, 7/11, and 11/7.
- Taking it further, this day of the week is also the same on pi day (3/14), Independence Day (7/4), Halloween (10/31) and Boxing Day (12/26).
Very quickly we know 13 days of the year that always fall on the same day of the week as one another.
