Enter a date below and it will tell you the name of the day that date was on:

How can I solve it myself?

It really is very simple. Let's assume the year is 2021. Follow the steps below:

Take the date and find the remainder when dividing by seven. For example, 25 divided by 7 is 3 with the remainder of 4. Remember this number for now.

Find the number associated with the month:

January: 1

February: 4

March: 4

April: 0

May: 2

June: 5

July: 0

August: 3

September: 6

October: 1

November: 4

December: 6

Although it may look hard, when you think up of ways to remember them, it becomes very easy. For example, since January is the first month, it has 1, and since December sounds sort of like dice, and a dice has six sides, then December is 6.

Now remember the number associated with the month, for example 6

Now this part you need to be careful about. We are doing the century now. Because it is 2021, then we subtract 1. Here is the list:

17xx: 4

18xx: 2

19xx: 0

20xx: -1

This is a repeating pattern, so 16xx is -1, and 15xx is 0, and so on.

Now for the year part. This part requires a bit more calculating. Since it is 2021, the year is 21. Now listen carefully.

First, add the number itself (21)

Next, add the quotient of that number divided by 4 (21/4 = 5 remainder 1, so we add 5 to make 21+5 = 26)

After that, get the remainder when divided by 7 (26/7 = 3 remainder 5, so our result is 5)

Finally, we have the result: 5!

Now add up all of your numbers. For us we have 4 + 6 - 1 + 5 = 14. But it is not finished yet.

Find the remainder when you divide by 7, in this case 14 divided by 7 is 2 remainder 0.

Match that with the corresponding day:

Sunday: 1

Monday: 2

Tuesday: 3

Wednesday: 4

Thursday: 5

Friday: 6

Saturday: 0

And that's it! Your answer! It just requires a bit of practice before you can do it without looking.

You can use this to figure out when your birthday will be or was this year, or any day actually.