Week numbers 123

123 has 52 ISO weeks. Week 1: Jan 4 – 10 · Week 52: Dec 27, 123 – Jan 2, 124

123 at a glance

Weeks in 12352
Week 1January 4, 123 – January 10, 123
Week 52December 27, 123 – January 2, 124
Days in 123365
Leap yearNo

All Weeks in 123

Week From To Month
Week 1 in 123 January 4, 123 January 10, 123 January
Week 2 in 123 January 11, 123 January 17, 123 January
Week 3 in 123 January 18, 123 January 24, 123 January
Week 4 in 123 January 25, 123 January 31, 123 January
Week 5 in 123 February 1, 123 February 7, 123 February
Week 6 in 123 February 8, 123 February 14, 123 February
Week 7 in 123 February 15, 123 February 21, 123 February
Week 8 in 123 February 22, 123 February 28, 123 February
Week 9 in 123 March 1, 123 March 7, 123 March
Week 10 in 123 March 8, 123 March 14, 123 March
Week 11 in 123 March 15, 123 March 21, 123 March
Week 12 in 123 March 22, 123 March 28, 123 March
Week 13 in 123 March 29, 123 April 4, 123 March / April
Week 14 in 123 April 5, 123 April 11, 123 April
Week 15 in 123 April 12, 123 April 18, 123 April
Week 16 in 123 April 19, 123 April 25, 123 April
Week 17 in 123 April 26, 123 May 2, 123 April / May
Week 18 in 123 May 3, 123 May 9, 123 May
Week 19 in 123 May 10, 123 May 16, 123 May
Week 20 in 123 May 17, 123 May 23, 123 May
Week 21 in 123 May 24, 123 May 30, 123 May
Week 22 in 123 May 31, 123 June 6, 123 May / June
Week 23 in 123 June 7, 123 June 13, 123 June
Week 24 in 123 June 14, 123 June 20, 123 June
Week 25 in 123 June 21, 123 June 27, 123 June
Week 26 in 123 June 28, 123 July 4, 123 June / July
Week 27 in 123 July 5, 123 July 11, 123 July
Week 28 in 123 July 12, 123 July 18, 123 July
Week 29 in 123 July 19, 123 July 25, 123 July
Week 30 in 123 July 26, 123 August 1, 123 July / August
Week 31 in 123 August 2, 123 August 8, 123 August
Week 32 in 123 August 9, 123 August 15, 123 August
Week 33 in 123 August 16, 123 August 22, 123 August
Week 34 in 123 August 23, 123 August 29, 123 August
Week 35 in 123 August 30, 123 September 5, 123 August / September
Week 36 in 123 September 6, 123 September 12, 123 September
Week 37 in 123 September 13, 123 September 19, 123 September
Week 38 in 123 September 20, 123 September 26, 123 September
Week 39 in 123 September 27, 123 October 3, 123 September / October
Week 40 in 123 October 4, 123 October 10, 123 October
Week 41 in 123 October 11, 123 October 17, 123 October
Week 42 in 123 October 18, 123 October 24, 123 October
Week 43 in 123 October 25, 123 October 31, 123 October
Week 44 in 123 November 1, 123 November 7, 123 November
Week 45 in 123 November 8, 123 November 14, 123 November
Week 46 in 123 November 15, 123 November 21, 123 November
Week 47 in 123 November 22, 123 November 28, 123 November
Week 48 in 123 November 29, 123 December 5, 123 November / December
Week 49 in 123 December 6, 123 December 12, 123 December
Week 50 in 123 December 13, 123 December 19, 123 December
Week 51 in 123 December 20, 123 December 26, 123 December
Week 52 in 123 December 27, 123 January 2, 124 December / January

Calendars 123

January 123
MoTuWeThFrSaSu
Week 53123
Week 145678910
Week 211121314151617
Week 318192021222324
Week 425262728293031
February 123
MoTuWeThFrSaSu
Week 51234567
Week 6891011121314
Week 715161718192021
Week 822232425262728
March 123
MoTuWeThFrSaSu
Week 91234567
Week 10891011121314
Week 1115161718192021
Week 1222232425262728
Week 13293031
April 123
MoTuWeThFrSaSu
Week 131234
Week 14567891011
Week 1512131415161718
Week 1619202122232425
Week 172627282930
May 123
MoTuWeThFrSaSu
Week 1712
Week 183456789
Week 1910111213141516
Week 2017181920212223
Week 2124252627282930
Week 2231
June 123
MoTuWeThFrSaSu
Week 22123456
Week 2378910111213
Week 2414151617181920
Week 2521222324252627
Week 26282930
July 123
MoTuWeThFrSaSu
Week 261234
Week 27567891011
Week 2812131415161718
Week 2919202122232425
Week 30262728293031
August 123
MoTuWeThFrSaSu
Week 301
Week 312345678
Week 329101112131415
Week 3316171819202122
Week 3423242526272829
Week 353031
September 123
MoTuWeThFrSaSu
Week 3512345
Week 366789101112
Week 3713141516171819
Week 3820212223242526
Week 3927282930
October 123
MoTuWeThFrSaSu
Week 39123
Week 4045678910
Week 4111121314151617
Week 4218192021222324
Week 4325262728293031
November 123
MoTuWeThFrSaSu
Week 441234567
Week 45891011121314
Week 4615161718192021
Week 4722232425262728
Week 482930
December 123
MoTuWeThFrSaSu
Week 112345
Week 496789101112
Week 5013141516171819
Week 5120212223242526
Week 522728293031

Download Calendar in printable A4 PDF

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 123 starts on January 4, 123 and ends on January 10, 123 (ISO 8601, Monday to Sunday). 123 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 123 have?

123 has 52 ISO weeks.

When does week 1 of 123 start?

Week 1 of 123 starts on January 4, 123 and ends on January 10, 123 (ISO 8601, Monday to Sunday).

When does the last week of 123 end?

Week 52 of 123 starts on December 27, 123 and ends on January 2, 124 (ISO 8601, Monday to Sunday).

Which years have 53 weeks?

The next years with 53 ISO weeks are 128, 133, 139, 144, 150.

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.