1981 — common year of 365 days, 1 January on a Thursday
1981 is a common year of 365 days, and 1 January falls on a Thursday. By ISO reckoning it runs 53 weeks.
- Leap year
- No
- Days in the year
- 365
- February
- 28
- 1 January
- Thursday
- 31 December
- Thursday
- ISO weeks
- 53
- Sexagenary sign
- XinYou
- Zodiac animal
- Rooster
- Previous leap year
- 1980
- Next leap year
- 1984
The rule for leap years
Divisible by 4 makes a leap year, divisible by 100 takes it back, divisible by 400 grants it again. That is why 1900 was not a leap year and 2000 was.
Days in each month
Years of 52 weeks and of 53
ISO counts a week as belonging to the year that holds its Thursday. A year runs to 53 weeks only when it contains 53 Thursdays — that is, when 1 January is a Thursday, or a Wednesday in a leap year.
The sixty-year cycle
Ten heavenly stems and twelve earthly branches advance together, one step each year, so the same pair returns only after sixty years. The animal alone repeats every twelve.
Nearby years
Decade by decade
1900s
1910s
1920s
1930s
1940s
1950s
1960s
1970s
1980s
1990s
2000s
2010s
2020s
2030s
2040s
2050s
2060s
2070s
2080s
2090s
2100s
How to read this
- Divisible by 4 is a leap year, by 100 is not, by 400 is again.
- A leap year holds 366 days, and February runs to the 29th.
- The ISO week count follows the Thursdays: 53 of them make a 53-week year.
- The sexagenary sign returns every 60 years, the animal every 12.
Frequently asked questions
Q. Is 1981 a leap year?
It is not. 1981 is not divisible by 4.
Q. What weekday is 1 January 1981?
A Thursday, and 31 December falls on a Thursday.
Q. How many weeks does 1981 have?
53 by ISO reckoning, because the year holds 53 Thursdays.
Q. Which zodiac animal is 1981?
The year of Xin-You, the Rooster. Note that the animal turns at the lunar new year, not on 1 January.