Week numbers 2025

Calendar 2025

2025 has 52 ISO weeks. Week 1 begins on December 30 and week 52 ends on December 28. The calendar above is set to print these numbers down the margin.

How ISO week numbering works

Week 1 of a year is the week containing its first Thursday — equivalently, the week containing 4 January. Weeks always run Monday to Sunday. Because of that rule, the first days of January can belong to the last week of the previous year, and the last days of December can already be week 1 of the next.

2025 has the usual 52 weeks. Years get a 53rd when they start on a Thursday, or on a Wednesday in a leap year.

Every week of 2025

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

Print a calendar with these numbers

Week numbers are a switch on every layout, not a separate product — see calendar with week numbers for where they appear in each one. They stay Monday-based even if you set the calendar itself to start on Sunday, so the numbers keep matching everybody else's.

Months of 2025

Other years