Week numbers 109

109 has 52 ISO weeks. Week 1: Dec 31, 108 – Jan 6, 109 · Week 52: Dec 23 – 29

109 at a glance

Weeks in 10952
Week 1December 31, 108 – January 6, 109
Week 52December 23, 109 – December 29, 109
Days in 109365
Leap yearNo

All Weeks in 109

Week From To Month
Week 1 in 109 December 31, 108 January 6, 109 December / January
Week 2 in 109 January 7, 109 January 13, 109 January
Week 3 in 109 January 14, 109 January 20, 109 January
Week 4 in 109 January 21, 109 January 27, 109 January
Week 5 in 109 January 28, 109 February 3, 109 January / February
Week 6 in 109 February 4, 109 February 10, 109 February
Week 7 in 109 February 11, 109 February 17, 109 February
Week 8 in 109 February 18, 109 February 24, 109 February
Week 9 in 109 February 25, 109 March 3, 109 February / March
Week 10 in 109 March 4, 109 March 10, 109 March
Week 11 in 109 March 11, 109 March 17, 109 March
Week 12 in 109 March 18, 109 March 24, 109 March
Week 13 in 109 March 25, 109 March 31, 109 March
Week 14 in 109 April 1, 109 April 7, 109 April
Week 15 in 109 April 8, 109 April 14, 109 April
Week 16 in 109 April 15, 109 April 21, 109 April
Week 17 in 109 April 22, 109 April 28, 109 April
Week 18 in 109 April 29, 109 May 5, 109 April / May
Week 19 in 109 May 6, 109 May 12, 109 May
Week 20 in 109 May 13, 109 May 19, 109 May
Week 21 in 109 May 20, 109 May 26, 109 May
Week 22 in 109 May 27, 109 June 2, 109 May / June
Week 23 in 109 June 3, 109 June 9, 109 June
Week 24 in 109 June 10, 109 June 16, 109 June
Week 25 in 109 June 17, 109 June 23, 109 June
Week 26 in 109 June 24, 109 June 30, 109 June
Week 27 in 109 July 1, 109 July 7, 109 July
Week 28 in 109 July 8, 109 July 14, 109 July
Week 29 in 109 July 15, 109 July 21, 109 July
Week 30 in 109 July 22, 109 July 28, 109 July
Week 31 in 109 July 29, 109 August 4, 109 July / August
Week 32 in 109 August 5, 109 August 11, 109 August
Week 33 in 109 August 12, 109 August 18, 109 August
Week 34 in 109 August 19, 109 August 25, 109 August
Week 35 in 109 August 26, 109 September 1, 109 August / September
Week 36 in 109 September 2, 109 September 8, 109 September
Week 37 in 109 September 9, 109 September 15, 109 September
Week 38 in 109 September 16, 109 September 22, 109 September
Week 39 in 109 September 23, 109 September 29, 109 September
Week 40 in 109 September 30, 109 October 6, 109 September / October
Week 41 in 109 October 7, 109 October 13, 109 October
Week 42 in 109 October 14, 109 October 20, 109 October
Week 43 in 109 October 21, 109 October 27, 109 October
Week 44 in 109 October 28, 109 November 3, 109 October / November
Week 45 in 109 November 4, 109 November 10, 109 November
Week 46 in 109 November 11, 109 November 17, 109 November
Week 47 in 109 November 18, 109 November 24, 109 November
Week 48 in 109 November 25, 109 December 1, 109 November / December
Week 49 in 109 December 2, 109 December 8, 109 December
Week 50 in 109 December 9, 109 December 15, 109 December
Week 51 in 109 December 16, 109 December 22, 109 December
Week 52 in 109 December 23, 109 December 29, 109 December

Calendars 109

January 109
MoTuWeThFrSaSu
Week 1123456
Week 278910111213
Week 314151617181920
Week 421222324252627
Week 528293031
February 109
MoTuWeThFrSaSu
Week 5123
Week 645678910
Week 711121314151617
Week 818192021222324
Week 925262728
March 109
MoTuWeThFrSaSu
Week 9123
Week 1045678910
Week 1111121314151617
Week 1218192021222324
Week 1325262728293031
April 109
MoTuWeThFrSaSu
Week 141234567
Week 15891011121314
Week 1615161718192021
Week 1722232425262728
Week 182930
May 109
MoTuWeThFrSaSu
Week 1812345
Week 196789101112
Week 2013141516171819
Week 2120212223242526
Week 222728293031
June 109
MoTuWeThFrSaSu
Week 2212
Week 233456789
Week 2410111213141516
Week 2517181920212223
Week 2624252627282930
July 109
MoTuWeThFrSaSu
Week 271234567
Week 28891011121314
Week 2915161718192021
Week 3022232425262728
Week 31293031
August 109
MoTuWeThFrSaSu
Week 311234
Week 32567891011
Week 3312131415161718
Week 3419202122232425
Week 35262728293031
September 109
MoTuWeThFrSaSu
Week 351
Week 362345678
Week 379101112131415
Week 3816171819202122
Week 3923242526272829
Week 4030
October 109
MoTuWeThFrSaSu
Week 40123456
Week 4178910111213
Week 4214151617181920
Week 4321222324252627
Week 4428293031
November 109
MoTuWeThFrSaSu
Week 44123
Week 4545678910
Week 4611121314151617
Week 4718192021222324
Week 48252627282930
December 109
MoTuWeThFrSaSu
Week 21
Week 492345678
Week 509101112131415
Week 5116171819202122
Week 5223242526272829
Week 13031

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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 109 starts on December 31, 108 and ends on January 6, 109 (ISO 8601, Monday to Sunday). 109 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 109 have?

109 has 52 ISO weeks.

When does week 1 of 109 start?

Week 1 of 109 starts on December 31, 108 and ends on January 6, 109 (ISO 8601, Monday to Sunday).

When does the last week of 109 end?

Week 52 of 109 starts on December 23, 109 and ends on December 29, 109 (ISO 8601, Monday to Sunday).

Which years have 53 weeks?

The next years with 53 ISO weeks are 111, 116, 122, 128, 133.

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.