The first Thursday decides
Week 1 is the week with the year's first Thursday, so January 1 can sit in the last week of the year before.
Week numbers 2029
Every ISO week of 2029 with its Monday and Sunday. 52 weeks in all.
Week numbers of 2029
52 weeks, each from Monday to Sunday.
Week 1
Jan 1 to Jan 7
Week 2
Jan 8 to Jan 14
Week 3
Jan 15 to Jan 21
Week 4
Jan 22 to Jan 28
Week 5
Jan 29 to Feb 4
Week 6
Feb 5 to Feb 11
Week 7
Feb 12 to Feb 18
Week 8
Feb 19 to Feb 25
Week 9
Feb 26 to Mar 4
Week 10
Mar 5 to Mar 11
Week 11
Mar 12 to Mar 18
Week 12
Mar 19 to Mar 25
Week 13
Mar 26 to Apr 1
Week 14
Apr 2 to Apr 8
Week 15
Apr 9 to Apr 15
Week 16
Apr 16 to Apr 22
Week 17
Apr 23 to Apr 29
Week 18
Apr 30 to May 6
Week 19
May 7 to May 13
Week 20
May 14 to May 20
Week 21
May 21 to May 27
Week 22
May 28 to Jun 3
Week 23
Jun 4 to Jun 10
Week 24
Jun 11 to Jun 17
Week 25
Jun 18 to Jun 24
Week 26
Jun 25 to Jul 1
Week 27
Jul 2 to Jul 8
Week 28
Jul 9 to Jul 15
Week 29
Jul 16 to Jul 22
Week 30
Jul 23 to Jul 29
Week 31
Jul 30 to Aug 5
Week 32
Aug 6 to Aug 12
Week 33
Aug 13 to Aug 19
Week 34
Aug 20 to Aug 26
Week 35
Aug 27 to Sep 2
Week 36
Sep 3 to Sep 9
Week 37
Sep 10 to Sep 16
Week 38
Sep 17 to Sep 23
Week 39
Sep 24 to Sep 30
Week 40
Oct 1 to Oct 7
Week 41
Oct 8 to Oct 14
Week 42
Oct 15 to Oct 21
Week 43
Oct 22 to Oct 28
Week 44
Oct 29 to Nov 4
Week 45
Nov 5 to Nov 11
Week 46
Nov 12 to Nov 18
Week 47
Nov 19 to Nov 25
Week 48
Nov 26 to Dec 2
Week 49
Dec 3 to Dec 9
Week 50
Dec 10 to Dec 16
Week 51
Dec 17 to Dec 23
Week 52
Dec 24 to Dec 30
How week numbers work
52 or 53 weeks
A year has 53 ISO weeks when January 1 is a Thursday, or a Wednesday in a leap year. 2029 has 52.
Why your calendar may differ
Some calendars, notably in the US, start weeks on Sunday and count the week with January 1 as week 1. That can differ from the ISO number by one.
Other years
More free tools
Frequently asked questions
Ask a questionBy ISO 8601, the standard most calendars and businesses use: a week runs from Monday to Sunday, and week 1 is the week that holds the year's first Thursday (so January 1 can be in week 52 or 53 of the year before, and December 29 to 31 can be in week 1 of the next). A year has 52 or 53 weeks.
52. A year has 53 ISO weeks when January 1 is a Thursday, or a Wednesday in a leap year.
Some calendars, notably in the US, start weeks on Sunday and count the week with January 1 as week 1. That system can differ from the ISO number by one. Check your calendar's settings: most offer ISO weeks.