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July 20, 1978 was a
Thursday

July 20, 1978 was a Thursday — that’s 17,490 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
Thursday
Day of year
201 of 365
ISO week
Week 29
Leap year?
No
Zodiac sign
Cancer
Days ago
17,490

How to solve: July 20, 1978

  1. 1
    Century anchor1900s→Wednesday (3)
    Practice →
  2. 2
    Divide by 1278 ÷ 12→6
    Practice →
  3. 3
    Remainder of 1278 % 12→6
    Practice →
  4. 4
    Divide remainder by 46 ÷ 4→1
    Practice →
  5. 5
    Year's doomsday(3 + 6 + 6 + 1) % 7→2 → Tuesday
    Practice →
  6. 6
    Month doomsdayJuly→11th
    Practice →
  7. 7
    Distance20 − 11→9
    Practice →
  8. 8
    Final answer(2 + 9) % 7→4 → Thursday

On this day in history

  • 1969Apollo 11 Moon Landing

Related dates

Day beforeJuly 19, 1978 — WednesdayDay afterJuly 21, 1978 — FridayOne year earlierJuly 20, 1977 — WednesdayOne year laterJuly 20, 1979 — Friday
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 'Black Thursday' refers to several historical events that occurred on a Thursday, including a major stock market crash in 1929?