What day of the week was March 21, 2005?

March 21, 2005 was a Monday. You can work it out in your head with the Doomsday algorithm — this page shows the full step-by-step calculation.

March 21, 2005 was a
Monday

March 21, 2005 was a Monday — that’s 7,798 days ago. Below you can see exactly how to work the weekday out in your head with the Doomsday algorithm, along with a few other facts about the date.

Weekday

Monday

Day of year

80 of 365

ISO week

Week 12

Leap year?

Zodiac sign

Aries

Days ago

7,798

How to solve: March 21, 2005

1
Century anchor2000s→ Tuesday (2)
Practice →
2
Divide by 125 ÷ 12→ 0
Practice →
3
Remainder of 125 % 12→ 5
Practice →
4
Divide remainder by 45 ÷ 4→ 1
Practice →
5
Year's doomsday(2 + 0 + 5 + 1) % 7→ 1 → Monday
Practice →
6
Month doomsdayMarch→ 14th
Practice →
7
Distance21 − 14→ 7
Practice →
8
Final answer(1 + 7) % 7→ 1 → Monday

Now you try

Same month, one different day. You already know March 14 is a doomsday — count from there.

March 1, 2005

On this day in history

2006Twitter is founded

Do this for any date, without looking it up

The Doomsday algorithm is six short steps. Most people get to a reliable answer in under 30 seconds after an afternoon of practice.

Learn the algorithm Play today’s challenge

Did you know? Did you know that Monday is the only day of the week when the U.S. stock market is more likely to decline than on any other day?

March 21, 2005 was aMonday

How to solve: March 21, 2005

Now you try

On this day in history

Do this for any date, without looking it up

March 21, 2005 was aMonday

How to solve: March 21, 2005

Now you try

On this day in history

Do this for any date, without looking it up

March 21, 2005 was a
Monday

March 21, 2005 was a
Monday