Ask Lemmy

It's a Friday. Because all that matters in any date with a year greater than four digits is the last four digits, and July 26, 2024 is today, and today is a Friday. 😊

But, if I didn't know July 26, 2024 were a Friday...

Step 1)

Starting numbers:

• Century is a multiple of 400: 2
• Century is 100 more than multiple of 400: 0
• Century is 200 more than multiple of 400: 5
• Century is 300 more than a multiple of 400: 3

2024 is in the century of the 2000s. 2000 is a perfect multiple of 400, so the starting number there is 2.

Step 2) 24 is a multiple of 12, specifically 12 x 2. Thus we add 2.

Step 3) 24 is a perfect multiple of 12 with zero years in excess, so we can add 0.

Step 4) There are no leap years in the 0 extra years beyond the closest multiple of 24, so we can add another 0.

Step 5) The Doomsday for July is 7/11. July 26th is 15 days after July 11th. 15 mod 7 is 1, so we add 1.

Step 6) 2 + 2 + 0 + 0 + 1 = 5

Step 7)

• 0 = Sunday (Noneday)
• 1 = Monday (Oneday)
• 2 = Tuesday (Twoday)
• 3 = Wednesday (Threesday)
• 4 = Thursday (Thorsday Foursday)
• 5 = Friday (Fiveday)
• 6 = Saturday (Sixaday)

Our total was 5, so the date July 26th, 2024 (or any year with the last four digits 2024) is a Friday.