Week numbers 104

104 has 52 ISO weeks. Week 1: Dec 31, 103 – Jan 6, 104 · Week 52: Dec 22 – 28

104 at a glance

Weeks in 10452
Week 1December 31, 103 – January 6, 104
Week 52December 22, 104 – December 28, 104
Days in 104366
Leap yearYes

All Weeks in 104

Week From To Month
Week 1 in 104 December 31, 103 January 6, 104 December / January
Week 2 in 104 January 7, 104 January 13, 104 January
Week 3 in 104 January 14, 104 January 20, 104 January
Week 4 in 104 January 21, 104 January 27, 104 January
Week 5 in 104 January 28, 104 February 3, 104 January / February
Week 6 in 104 February 4, 104 February 10, 104 February
Week 7 in 104 February 11, 104 February 17, 104 February
Week 8 in 104 February 18, 104 February 24, 104 February
Week 9 in 104 February 25, 104 March 2, 104 February / March
Week 10 in 104 March 3, 104 March 9, 104 March
Week 11 in 104 March 10, 104 March 16, 104 March
Week 12 in 104 March 17, 104 March 23, 104 March
Week 13 in 104 March 24, 104 March 30, 104 March
Week 14 in 104 March 31, 104 April 6, 104 March / April
Week 15 in 104 April 7, 104 April 13, 104 April
Week 16 in 104 April 14, 104 April 20, 104 April
Week 17 in 104 April 21, 104 April 27, 104 April
Week 18 in 104 April 28, 104 May 4, 104 April / May
Week 19 in 104 May 5, 104 May 11, 104 May
Week 20 in 104 May 12, 104 May 18, 104 May
Week 21 in 104 May 19, 104 May 25, 104 May
Week 22 in 104 May 26, 104 June 1, 104 May / June
Week 23 in 104 June 2, 104 June 8, 104 June
Week 24 in 104 June 9, 104 June 15, 104 June
Week 25 in 104 June 16, 104 June 22, 104 June
Week 26 in 104 June 23, 104 June 29, 104 June
Week 27 in 104 June 30, 104 July 6, 104 June / July
Week 28 in 104 July 7, 104 July 13, 104 July
Week 29 in 104 July 14, 104 July 20, 104 July
Week 30 in 104 July 21, 104 July 27, 104 July
Week 31 in 104 July 28, 104 August 3, 104 July / August
Week 32 in 104 August 4, 104 August 10, 104 August
Week 33 in 104 August 11, 104 August 17, 104 August
Week 34 in 104 August 18, 104 August 24, 104 August
Week 35 in 104 August 25, 104 August 31, 104 August
Week 36 in 104 September 1, 104 September 7, 104 September
Week 37 in 104 September 8, 104 September 14, 104 September
Week 38 in 104 September 15, 104 September 21, 104 September
Week 39 in 104 September 22, 104 September 28, 104 September
Week 40 in 104 September 29, 104 October 5, 104 September / October
Week 41 in 104 October 6, 104 October 12, 104 October
Week 42 in 104 October 13, 104 October 19, 104 October
Week 43 in 104 October 20, 104 October 26, 104 October
Week 44 in 104 October 27, 104 November 2, 104 October / November
Week 45 in 104 November 3, 104 November 9, 104 November
Week 46 in 104 November 10, 104 November 16, 104 November
Week 47 in 104 November 17, 104 November 23, 104 November
Week 48 in 104 November 24, 104 November 30, 104 November
Week 49 in 104 December 1, 104 December 7, 104 December
Week 50 in 104 December 8, 104 December 14, 104 December
Week 51 in 104 December 15, 104 December 21, 104 December
Week 52 in 104 December 22, 104 December 28, 104 December

Calendars 104

January 104
MoTuWeThFrSaSu
Week 1123456
Week 278910111213
Week 314151617181920
Week 421222324252627
Week 528293031
February 104
MoTuWeThFrSaSu
Week 5123
Week 645678910
Week 711121314151617
Week 818192021222324
Week 92526272829
March 104
MoTuWeThFrSaSu
Week 912
Week 103456789
Week 1110111213141516
Week 1217181920212223
Week 1324252627282930
Week 1431
April 104
MoTuWeThFrSaSu
Week 14123456
Week 1578910111213
Week 1614151617181920
Week 1721222324252627
Week 18282930
May 104
MoTuWeThFrSaSu
Week 181234
Week 19567891011
Week 2012131415161718
Week 2119202122232425
Week 22262728293031
June 104
MoTuWeThFrSaSu
Week 221
Week 232345678
Week 249101112131415
Week 2516171819202122
Week 2623242526272829
Week 2730
July 104
MoTuWeThFrSaSu
Week 27123456
Week 2878910111213
Week 2914151617181920
Week 3021222324252627
Week 3128293031
August 104
MoTuWeThFrSaSu
Week 31123
Week 3245678910
Week 3311121314151617
Week 3418192021222324
Week 3525262728293031
September 104
MoTuWeThFrSaSu
Week 361234567
Week 37891011121314
Week 3815161718192021
Week 3922232425262728
Week 402930
October 104
MoTuWeThFrSaSu
Week 4012345
Week 416789101112
Week 4213141516171819
Week 4320212223242526
Week 442728293031
November 104
MoTuWeThFrSaSu
Week 4412
Week 453456789
Week 4610111213141516
Week 4717181920212223
Week 4824252627282930
December 104
MoTuWeThFrSaSu
Week 491234567
Week 50891011121314
Week 5115161718192021
Week 5222232425262728
Week 1293031

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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 104 starts on December 31, 103 and ends on January 6, 104 (ISO 8601, Monday to Sunday). 104 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 104 have?

104 has 52 ISO weeks.

When does week 1 of 104 start?

Week 1 of 104 starts on December 31, 103 and ends on January 6, 104 (ISO 8601, Monday to Sunday).

When does the last week of 104 end?

Week 52 of 104 starts on December 22, 104 and ends on December 28, 104 (ISO 8601, Monday to Sunday).

Which years have 53 weeks?

The next years with 53 ISO weeks are 105, 111, 116, 122, 128.

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.