How to Find the Day of the Week for Any Date

For example, what day of the week was December 26, 2004, when the tsunami struck the Indian Ocean? Follow the example as you read along:

1. Take the last two digits of the year.
2. Add to that one–quarter of those two digits (discard any remainder).

3. Add to that the day of the month and the Month Key number for that month:

   Read Next

   • When Is Easter? Why It Falls So Late in 2025.
   • Origin of Day Names: Where Did the Days of the Week Come From?
   • Why the Week Has Seven Days

   January = 1	June = 5
   …leap year = 0	July = 0
   February = 4	August = 3
   …leap year = 3	September = 6
   March = 4	October = 1
   April = 0	November = 4
   May = 2	December = 6

4. Divide the sum by 7. The remainder is the day of the week! One is Sunday, two is Monday, and so on. If there is no remainder, the day is Saturday. 
   [Note: At this step, it may be easiest to use long division to get the remainder. When using a calculator, after you divide the sum by 7, you’ll need to multiply the numbers after the decimal (not the whole number) in the result by 7 and then round to the nearest whole number to get the remainder.]

Note: 

• If you’re searching for a week before 1900, add 2 to the sum before dividing; before 1800, add 4.
• The formula doesn’t work for days before 1753.
• From 2000 to 2099, subtract 1 from the sum before dividing.

Here’s an Example:

A tsunami occurred in the Indian Ocean on December 26, 2004.

Sum: 37

Because 2004 is in the range of 2000 to 2099, subtract 1 from 37. This yields 36.

36 divided by 7 = 5, with a remainder of 1. The tsunami took place on Sunday, the first day of the week.

Monday’s child is fair of face, 
Tuesday’s child is full of grace, 
Wednesday’s child is full of woe, 
Thursday’s child has far to go, 
Friday’s child is loving and giving, 
Saturday’s child works hard for a living, 
And the child that is born on the Sabbath Day, 
Is bonny and blithe and good and gay. 
–an old English nursery rhyme