Week numbers 221

221 has 52 ISO weeks. Week 1: Jan 1 – 7 · Week 52: Dec 24 – 30

221 at a glance

Weeks in 22152
Week 1January 1, 221 – January 7, 221
Week 52December 24, 221 – December 30, 221
Days in 221365
Leap yearNo

All Weeks in 221

Week From To Month
Week 1 in 221 January 1, 221 January 7, 221 January
Week 2 in 221 January 8, 221 January 14, 221 January
Week 3 in 221 January 15, 221 January 21, 221 January
Week 4 in 221 January 22, 221 January 28, 221 January
Week 5 in 221 January 29, 221 February 4, 221 January / February
Week 6 in 221 February 5, 221 February 11, 221 February
Week 7 in 221 February 12, 221 February 18, 221 February
Week 8 in 221 February 19, 221 February 25, 221 February
Week 9 in 221 February 26, 221 March 4, 221 February / March
Week 10 in 221 March 5, 221 March 11, 221 March
Week 11 in 221 March 12, 221 March 18, 221 March
Week 12 in 221 March 19, 221 March 25, 221 March
Week 13 in 221 March 26, 221 April 1, 221 March / April
Week 14 in 221 April 2, 221 April 8, 221 April
Week 15 in 221 April 9, 221 April 15, 221 April
Week 16 in 221 April 16, 221 April 22, 221 April
Week 17 in 221 April 23, 221 April 29, 221 April
Week 18 in 221 April 30, 221 May 6, 221 April / May
Week 19 in 221 May 7, 221 May 13, 221 May
Week 20 in 221 May 14, 221 May 20, 221 May
Week 21 in 221 May 21, 221 May 27, 221 May
Week 22 in 221 May 28, 221 June 3, 221 May / June
Week 23 in 221 June 4, 221 June 10, 221 June
Week 24 in 221 June 11, 221 June 17, 221 June
Week 25 in 221 June 18, 221 June 24, 221 June
Week 26 in 221 June 25, 221 July 1, 221 June / July
Week 27 in 221 July 2, 221 July 8, 221 July
Week 28 in 221 July 9, 221 July 15, 221 July
Week 29 in 221 July 16, 221 July 22, 221 July
Week 30 in 221 July 23, 221 July 29, 221 July
Week 31 in 221 July 30, 221 August 5, 221 July / August
Week 32 in 221 August 6, 221 August 12, 221 August
Week 33 in 221 August 13, 221 August 19, 221 August
Week 34 in 221 August 20, 221 August 26, 221 August
Week 35 in 221 August 27, 221 September 2, 221 August / September
Week 36 in 221 September 3, 221 September 9, 221 September
Week 37 in 221 September 10, 221 September 16, 221 September
Week 38 in 221 September 17, 221 September 23, 221 September
Week 39 in 221 September 24, 221 September 30, 221 September
Week 40 in 221 October 1, 221 October 7, 221 October
Week 41 in 221 October 8, 221 October 14, 221 October
Week 42 in 221 October 15, 221 October 21, 221 October
Week 43 in 221 October 22, 221 October 28, 221 October
Week 44 in 221 October 29, 221 November 4, 221 October / November
Week 45 in 221 November 5, 221 November 11, 221 November
Week 46 in 221 November 12, 221 November 18, 221 November
Week 47 in 221 November 19, 221 November 25, 221 November
Week 48 in 221 November 26, 221 December 2, 221 November / December
Week 49 in 221 December 3, 221 December 9, 221 December
Week 50 in 221 December 10, 221 December 16, 221 December
Week 51 in 221 December 17, 221 December 23, 221 December
Week 52 in 221 December 24, 221 December 30, 221 December

Calendars 221

January 221
MoTuWeThFrSaSu
Week 11234567
Week 2891011121314
Week 315161718192021
Week 422232425262728
Week 5293031
February 221
MoTuWeThFrSaSu
Week 51234
Week 6567891011
Week 712131415161718
Week 819202122232425
Week 9262728
March 221
MoTuWeThFrSaSu
Week 91234
Week 10567891011
Week 1112131415161718
Week 1219202122232425
Week 13262728293031
April 221
MoTuWeThFrSaSu
Week 131
Week 142345678
Week 159101112131415
Week 1616171819202122
Week 1723242526272829
Week 1830
May 221
MoTuWeThFrSaSu
Week 18123456
Week 1978910111213
Week 2014151617181920
Week 2121222324252627
Week 2228293031
June 221
MoTuWeThFrSaSu
Week 22123
Week 2345678910
Week 2411121314151617
Week 2518192021222324
Week 26252627282930
July 221
MoTuWeThFrSaSu
Week 261
Week 272345678
Week 289101112131415
Week 2916171819202122
Week 3023242526272829
Week 313031
August 221
MoTuWeThFrSaSu
Week 3112345
Week 326789101112
Week 3313141516171819
Week 3420212223242526
Week 352728293031
September 221
MoTuWeThFrSaSu
Week 3512
Week 363456789
Week 3710111213141516
Week 3817181920212223
Week 3924252627282930
October 221
MoTuWeThFrSaSu
Week 401234567
Week 41891011121314
Week 4215161718192021
Week 4322232425262728
Week 44293031
November 221
MoTuWeThFrSaSu
Week 441234
Week 45567891011
Week 4612131415161718
Week 4719202122232425
Week 482627282930
December 221
MoTuWeThFrSaSu
Week 212
Week 493456789
Week 5010111213141516
Week 5117181920212223
Week 5224252627282930
Week 131

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Find the week number of a date

How week numbers are counted

Most of the world numbers weeks according to the ISO 8601 standard. A week starts on Monday, and week 1 is the week that contains the first Thursday of the year, which is always the week that contains 4 January.

Week 1 of 221 starts on January 1, 221 and ends on January 7, 221 (ISO 8601, Monday to Sunday). 221 has 52 ISO weeks.

Because of this rule, the first days of January can belong to the last week of the previous year, and the last days of December can belong to week 1 of the next year.

In the United States, weeks usually start on Sunday and week 1 is the week that contains 1 January, so the US week number can differ from the ISO week number.

Frequently Asked Questions (FAQ)

How many weeks does 221 have?

221 has 52 ISO weeks.

When does week 1 of 221 start?

Week 1 of 221 starts on January 1, 221 and ends on January 7, 221 (ISO 8601, Monday to Sunday).

When does the last week of 221 end?

Week 52 of 221 starts on December 24, 221 and ends on December 30, 221 (ISO 8601, Monday to Sunday).

Which years have 53 weeks?

The next years with 53 ISO weeks are 224, 229, 235, 240, 246.

Why do the US and Europe show different week numbers?

Europe follows ISO 8601: weeks start on Monday and week 1 is the week with the first Thursday of the year. In the US, weeks usually start on Sunday and week 1 is the week that contains 1 January, so the two numbers can differ by one.