Week numbers 660

660 has 52 ISO weeks. Week 1: Jan 2 – 8 · Week 52: Dec 24 – 30

660 at a glance

Weeks in 66052
Week 1January 2, 660 – January 8, 660
Week 52December 24, 660 – December 30, 660
Days in 660366
Leap yearYes

All Weeks in 660

Week From To Month
Week 1 in 660 January 2, 660 January 8, 660 January
Week 2 in 660 January 9, 660 January 15, 660 January
Week 3 in 660 January 16, 660 January 22, 660 January
Week 4 in 660 January 23, 660 January 29, 660 January
Week 5 in 660 January 30, 660 February 5, 660 January / February
Week 6 in 660 February 6, 660 February 12, 660 February
Week 7 in 660 February 13, 660 February 19, 660 February
Week 8 in 660 February 20, 660 February 26, 660 February
Week 9 in 660 February 27, 660 March 4, 660 February / March
Week 10 in 660 March 5, 660 March 11, 660 March
Week 11 in 660 March 12, 660 March 18, 660 March
Week 12 in 660 March 19, 660 March 25, 660 March
Week 13 in 660 March 26, 660 April 1, 660 March / April
Week 14 in 660 April 2, 660 April 8, 660 April
Week 15 in 660 April 9, 660 April 15, 660 April
Week 16 in 660 April 16, 660 April 22, 660 April
Week 17 in 660 April 23, 660 April 29, 660 April
Week 18 in 660 April 30, 660 May 6, 660 April / May
Week 19 in 660 May 7, 660 May 13, 660 May
Week 20 in 660 May 14, 660 May 20, 660 May
Week 21 in 660 May 21, 660 May 27, 660 May
Week 22 in 660 May 28, 660 June 3, 660 May / June
Week 23 in 660 June 4, 660 June 10, 660 June
Week 24 in 660 June 11, 660 June 17, 660 June
Week 25 in 660 June 18, 660 June 24, 660 June
Week 26 in 660 June 25, 660 July 1, 660 June / July
Week 27 in 660 July 2, 660 July 8, 660 July
Week 28 in 660 July 9, 660 July 15, 660 July
Week 29 in 660 July 16, 660 July 22, 660 July
Week 30 in 660 July 23, 660 July 29, 660 July
Week 31 in 660 July 30, 660 August 5, 660 July / August
Week 32 in 660 August 6, 660 August 12, 660 August
Week 33 in 660 August 13, 660 August 19, 660 August
Week 34 in 660 August 20, 660 August 26, 660 August
Week 35 in 660 August 27, 660 September 2, 660 August / September
Week 36 in 660 September 3, 660 September 9, 660 September
Week 37 in 660 September 10, 660 September 16, 660 September
Week 38 in 660 September 17, 660 September 23, 660 September
Week 39 in 660 September 24, 660 September 30, 660 September
Week 40 in 660 October 1, 660 October 7, 660 October
Week 41 in 660 October 8, 660 October 14, 660 October
Week 42 in 660 October 15, 660 October 21, 660 October
Week 43 in 660 October 22, 660 October 28, 660 October
Week 44 in 660 October 29, 660 November 4, 660 October / November
Week 45 in 660 November 5, 660 November 11, 660 November
Week 46 in 660 November 12, 660 November 18, 660 November
Week 47 in 660 November 19, 660 November 25, 660 November
Week 48 in 660 November 26, 660 December 2, 660 November / December
Week 49 in 660 December 3, 660 December 9, 660 December
Week 50 in 660 December 10, 660 December 16, 660 December
Week 51 in 660 December 17, 660 December 23, 660 December
Week 52 in 660 December 24, 660 December 30, 660 December

Calendars 660

January 660
MoTuWeThFrSaSu
Week 521
Week 12345678
Week 29101112131415
Week 316171819202122
Week 423242526272829
Week 53031
February 660
MoTuWeThFrSaSu
Week 512345
Week 66789101112
Week 713141516171819
Week 820212223242526
Week 9272829
March 660
MoTuWeThFrSaSu
Week 91234
Week 10567891011
Week 1112131415161718
Week 1219202122232425
Week 13262728293031
April 660
MoTuWeThFrSaSu
Week 131
Week 142345678
Week 159101112131415
Week 1616171819202122
Week 1723242526272829
Week 1830
May 660
MoTuWeThFrSaSu
Week 18123456
Week 1978910111213
Week 2014151617181920
Week 2121222324252627
Week 2228293031
June 660
MoTuWeThFrSaSu
Week 22123
Week 2345678910
Week 2411121314151617
Week 2518192021222324
Week 26252627282930
July 660
MoTuWeThFrSaSu
Week 261
Week 272345678
Week 289101112131415
Week 2916171819202122
Week 3023242526272829
Week 313031
August 660
MoTuWeThFrSaSu
Week 3112345
Week 326789101112
Week 3313141516171819
Week 3420212223242526
Week 352728293031
September 660
MoTuWeThFrSaSu
Week 3512
Week 363456789
Week 3710111213141516
Week 3817181920212223
Week 3924252627282930
October 660
MoTuWeThFrSaSu
Week 401234567
Week 41891011121314
Week 4215161718192021
Week 4322232425262728
Week 44293031
November 660
MoTuWeThFrSaSu
Week 441234
Week 45567891011
Week 4612131415161718
Week 4719202122232425
Week 482627282930
December 660
MoTuWeThFrSaSu
Week 112
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 660 starts on January 2, 660 and ends on January 8, 660 (ISO 8601, Monday to Sunday). 660 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 660 have?

660 has 52 ISO weeks.

When does week 1 of 660 start?

Week 1 of 660 starts on January 2, 660 and ends on January 8, 660 (ISO 8601, Monday to Sunday).

When does the last week of 660 end?

Week 52 of 660 starts on December 24, 660 and ends on December 30, 660 (ISO 8601, Monday to Sunday).

Which years have 53 weeks?

The next years with 53 ISO weeks are 663, 668, 674, 680, 685.

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.