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Calendar

2021 calendar

All twelve months of 2021, with ISO week numbers. Weeks start on Monday; switch to Sunday if you prefer.

Weeks start on
January — January, with ISO week numbers
WkMonTueWedThuFriSatSun
53123
145678910
211121314151617
318192021222324
425262728293031
February — February, with ISO week numbers
WkMonTueWedThuFriSatSun
51234567
6891011121314
715161718192021
822232425262728
March — March, with ISO week numbers
WkMonTueWedThuFriSatSun
91234567
10891011121314
1115161718192021
1222232425262728
13293031
April — April, with ISO week numbers
WkMonTueWedThuFriSatSun
131234
14567891011
1512131415161718
1619202122232425
172627282930
May — May, with ISO week numbers
WkMonTueWedThuFriSatSun
1712
183456789
1910111213141516
2017181920212223
2124252627282930
2231
June — June, with ISO week numbers
WkMonTueWedThuFriSatSun
22123456
2378910111213
2414151617181920
2521222324252627
26282930
July — July, with ISO week numbers
WkMonTueWedThuFriSatSun
261234
27567891011
2812131415161718
2919202122232425
30262728293031
August — August, with ISO week numbers
WkMonTueWedThuFriSatSun
301
312345678
329101112131415
3316171819202122
3423242526272829
353031
September — September, with ISO week numbers
WkMonTueWedThuFriSatSun
3512345
366789101112
3713141516171819
3820212223242526
3927282930
October — October, with ISO week numbers
WkMonTueWedThuFriSatSun
39123
4045678910
4111121314151617
4218192021222324
4325262728293031
November — November, with ISO week numbers
WkMonTueWedThuFriSatSun
441234567
45891011121314
4615161718192021
4722232425262728
482930
December — December, with ISO week numbers
WkMonTueWedThuFriSatSun
4812345
496789101112
5013141516171819
5120212223242526
522728293031

Calendar

2021 at a glance

01Days

365

02ISO weeks

52

2021 has 52 ISO weeks; week 1 starts on Monday, 4 January 2021.

03Starts on

Friday, 1 January 2021

04Ends on

Friday, 31 December 2021

05Is 2021 a leap year?

2021 is not a leap year: 365 days. The next leap year is 2024.

Clock changes

Clock changes in 2021

01European Union and the UK (shown in Paris time)

Sunday, 28 March 2021 at 02:00: clocks go forward 1 hour to 03:00 (CET → CEST).

Sunday, 31 October 2021 at 03:00: clocks go back 1 hour to 02:00 (CEST → CET).

The EU and the UK change at 01:00 UTC on the last Sunday of March and of October, at the same moment in every country.

02United States and most of Canada (shown in New York time)

Sunday, 14 March 2021 at 02:00: clocks go forward 1 hour to 03:00 (EST → EDT).

Sunday, 7 November 2021 at 02:00: clocks go back 1 hour to 01:00 (EDT → EST).

03Your time zone

How it works

ISO week numbers

ISO 8601 weeks start on Monday, and week 1 is the week that contains the year’s first Thursday (equivalently, 4 January). A year therefore has 52 or 53 weeks, and the first days of January can belong to the last week of the previous year.

The Gregorian leap-year rule: a year divisible by 4 is a leap year, except years divisible by 100, unless they are also divisible by 400. So 2000 was a leap year and 2100 will not be.

Other years

Questions

Good to know

How many weeks are there in 2021?

2021 has 52 ISO weeks; week 1 starts on Monday, 4 January 2021.

Is 2021 a leap year?

2021 is not a leap year: 365 days. The next leap year is 2024.

When do the clocks change in 2021?

In the EU and the UK: Sunday, 28 March 2021 at 02:00: clocks go forward 1 hour to 03:00 (CET → CEST); Sunday, 31 October 2021 at 03:00: clocks go back 1 hour to 02:00 (CEST → CET). In the US: Sunday, 14 March 2021 at 02:00: clocks go forward 1 hour to 03:00 (EST → EDT); Sunday, 7 November 2021 at 02:00: clocks go back 1 hour to 01:00 (EDT → EST).