What the day logo
What the Day
LearnPracticePlayDailyGuides
LearnGuidesPracticePlayDaily challengeLeaderboardAboutContactPrivacy
Copyright © 2026 Jesper Kiledal
All rights reserved
☕Buy me a coffee
What the day logo
What the Day
LearnPracticePlayDailyGuides

August 25, 1980 was a
Monday

August 25, 1980 was a Monday — that’s 16,724 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
238 of 366
ISO week
Week 35
Leap year?
Yes
Zodiac sign
Virgo
Days ago
16,724

How to solve: August 25, 1980

  1. 1
    Century anchor1900s→Wednesday (3)
    Practice →
  2. 2
    Divide by 1280 ÷ 12→6
    Practice →
  3. 3
    Remainder of 1280 % 12→8
    Practice →
  4. 4
    Divide remainder by 48 ÷ 4→2
    Practice →
  5. 5
    Year's doomsday(3 + 6 + 8 + 2) % 7→5 → Friday
    Practice →
  6. 6
    Month doomsdayAugust→8th
    Practice →
  7. 7
    Distance25 − 8→17
    Practice →
  8. 8
    Final answer(5 + 17) % 7→1 → Monday

On this day in history

  • 1939The Wizard of Oz is released

Related dates

Day beforeAugust 24, 1980 — SundayDay afterAugust 26, 1980 — TuesdayOne year earlierAugust 25, 1979 — SaturdayOne year laterAugust 25, 1981 — Tuesday
Want to be able to do this for any date in seconds? Read the guide or practice the algorithm.
Did you know? Did you know that the third Monday of January is often referred to as 'Blue Monday' and is considered the most depressing day of the year?