Week numbers 423

423 has 52 ISO weeks. Week 1: Jan 2 – 8 · Week 52: Dec 25 – 31

423 at a glance

Weeks in 42352
Week 1January 2, 423 – January 8, 423
Week 52December 25, 423 – December 31, 423
Days in 423365
Leap yearNo

All Weeks in 423

Week From To Month
Week 1 in 423 January 2, 423 January 8, 423 January
Week 2 in 423 January 9, 423 January 15, 423 January
Week 3 in 423 January 16, 423 January 22, 423 January
Week 4 in 423 January 23, 423 January 29, 423 January
Week 5 in 423 January 30, 423 February 5, 423 January / February
Week 6 in 423 February 6, 423 February 12, 423 February
Week 7 in 423 February 13, 423 February 19, 423 February
Week 8 in 423 February 20, 423 February 26, 423 February
Week 9 in 423 February 27, 423 March 5, 423 February / March
Week 10 in 423 March 6, 423 March 12, 423 March
Week 11 in 423 March 13, 423 March 19, 423 March
Week 12 in 423 March 20, 423 March 26, 423 March
Week 13 in 423 March 27, 423 April 2, 423 March / April
Week 14 in 423 April 3, 423 April 9, 423 April
Week 15 in 423 April 10, 423 April 16, 423 April
Week 16 in 423 April 17, 423 April 23, 423 April
Week 17 in 423 April 24, 423 April 30, 423 April
Week 18 in 423 May 1, 423 May 7, 423 May
Week 19 in 423 May 8, 423 May 14, 423 May
Week 20 in 423 May 15, 423 May 21, 423 May
Week 21 in 423 May 22, 423 May 28, 423 May
Week 22 in 423 May 29, 423 June 4, 423 May / June
Week 23 in 423 June 5, 423 June 11, 423 June
Week 24 in 423 June 12, 423 June 18, 423 June
Week 25 in 423 June 19, 423 June 25, 423 June
Week 26 in 423 June 26, 423 July 2, 423 June / July
Week 27 in 423 July 3, 423 July 9, 423 July
Week 28 in 423 July 10, 423 July 16, 423 July
Week 29 in 423 July 17, 423 July 23, 423 July
Week 30 in 423 July 24, 423 July 30, 423 July
Week 31 in 423 July 31, 423 August 6, 423 July / August
Week 32 in 423 August 7, 423 August 13, 423 August
Week 33 in 423 August 14, 423 August 20, 423 August
Week 34 in 423 August 21, 423 August 27, 423 August
Week 35 in 423 August 28, 423 September 3, 423 August / September
Week 36 in 423 September 4, 423 September 10, 423 September
Week 37 in 423 September 11, 423 September 17, 423 September
Week 38 in 423 September 18, 423 September 24, 423 September
Week 39 in 423 September 25, 423 October 1, 423 September / October
Week 40 in 423 October 2, 423 October 8, 423 October
Week 41 in 423 October 9, 423 October 15, 423 October
Week 42 in 423 October 16, 423 October 22, 423 October
Week 43 in 423 October 23, 423 October 29, 423 October
Week 44 in 423 October 30, 423 November 5, 423 October / November
Week 45 in 423 November 6, 423 November 12, 423 November
Week 46 in 423 November 13, 423 November 19, 423 November
Week 47 in 423 November 20, 423 November 26, 423 November
Week 48 in 423 November 27, 423 December 3, 423 November / December
Week 49 in 423 December 4, 423 December 10, 423 December
Week 50 in 423 December 11, 423 December 17, 423 December
Week 51 in 423 December 18, 423 December 24, 423 December
Week 52 in 423 December 25, 423 December 31, 423 December

Calendars 423

January 423
MoTuWeThFrSaSu
Week 521
Week 12345678
Week 29101112131415
Week 316171819202122
Week 423242526272829
Week 53031
February 423
MoTuWeThFrSaSu
Week 512345
Week 66789101112
Week 713141516171819
Week 820212223242526
Week 92728
March 423
MoTuWeThFrSaSu
Week 912345
Week 106789101112
Week 1113141516171819
Week 1220212223242526
Week 132728293031
April 423
MoTuWeThFrSaSu
Week 1312
Week 143456789
Week 1510111213141516
Week 1617181920212223
Week 1724252627282930
May 423
MoTuWeThFrSaSu
Week 181234567
Week 19891011121314
Week 2015161718192021
Week 2122232425262728
Week 22293031
June 423
MoTuWeThFrSaSu
Week 221234
Week 23567891011
Week 2412131415161718
Week 2519202122232425
Week 262627282930
July 423
MoTuWeThFrSaSu
Week 2612
Week 273456789
Week 2810111213141516
Week 2917181920212223
Week 3024252627282930
Week 3131
August 423
MoTuWeThFrSaSu
Week 31123456
Week 3278910111213
Week 3314151617181920
Week 3421222324252627
Week 3528293031
September 423
MoTuWeThFrSaSu
Week 35123
Week 3645678910
Week 3711121314151617
Week 3818192021222324
Week 39252627282930
October 423
MoTuWeThFrSaSu
Week 391
Week 402345678
Week 419101112131415
Week 4216171819202122
Week 4323242526272829
Week 443031
November 423
MoTuWeThFrSaSu
Week 4412345
Week 456789101112
Week 4613141516171819
Week 4720212223242526
Week 4827282930
December 423
MoTuWeThFrSaSu
Week 1123
Week 4945678910
Week 5011121314151617
Week 5118192021222324
Week 5225262728293031

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 423 starts on January 2, 423 and ends on January 8, 423 (ISO 8601, Monday to Sunday). 423 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 423 have?

423 has 52 ISO weeks.

When does week 1 of 423 start?

Week 1 of 423 starts on January 2, 423 and ends on January 8, 423 (ISO 8601, Monday to Sunday).

When does the last week of 423 end?

Week 52 of 423 starts on December 25, 423 and ends on December 31, 423 (ISO 8601, Monday to Sunday).

Which years have 53 weeks?

The next years with 53 ISO weeks are 426, 432, 437, 443, 448.

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.