ISO week calendar 2025
All 52 ISO weeks of 2025, with the Monday and Sunday that bound each one.
The ISO year 2025 has 52 weeks. Week 1 starts on December 30, 2024 and week 52 ends on December 28, 2025. Every row below is one ISO week, Monday through Sunday.
| ISO week | Monday | Sunday |
|---|---|---|
| Week 1 | December 30, 2024 | January 5, 2025 |
| Week 2 | January 6, 2025 | January 12, 2025 |
| Week 3 | January 13, 2025 | January 19, 2025 |
| Week 4 | January 20, 2025 | January 26, 2025 |
| Week 5 | January 27, 2025 | February 2, 2025 |
| Week 6 | February 3, 2025 | February 9, 2025 |
| Week 7 | February 10, 2025 | February 16, 2025 |
| Week 8 | February 17, 2025 | February 23, 2025 |
| Week 9 | February 24, 2025 | March 2, 2025 |
| Week 10 | March 3, 2025 | March 9, 2025 |
| Week 11 | March 10, 2025 | March 16, 2025 |
| Week 12 | March 17, 2025 | March 23, 2025 |
| Week 13 | March 24, 2025 | March 30, 2025 |
| Week 14 | March 31, 2025 | April 6, 2025 |
| Week 15 | April 7, 2025 | April 13, 2025 |
| Week 16 | April 14, 2025 | April 20, 2025 |
| Week 17 | April 21, 2025 | April 27, 2025 |
| Week 18 | April 28, 2025 | May 4, 2025 |
| Week 19 | May 5, 2025 | May 11, 2025 |
| Week 20 | May 12, 2025 | May 18, 2025 |
| Week 21 | May 19, 2025 | May 25, 2025 |
| Week 22 | May 26, 2025 | June 1, 2025 |
| Week 23 | June 2, 2025 | June 8, 2025 |
| Week 24 | June 9, 2025 | June 15, 2025 |
| Week 25 | June 16, 2025 | June 22, 2025 |
| Week 26 | June 23, 2025 | June 29, 2025 |
| Week 27 | June 30, 2025 | July 6, 2025 |
| Week 28 | July 7, 2025 | July 13, 2025 |
| Week 29 | July 14, 2025 | July 20, 2025 |
| Week 30 | July 21, 2025 | July 27, 2025 |
| Week 31 | July 28, 2025 | August 3, 2025 |
| Week 32 | August 4, 2025 | August 10, 2025 |
| Week 33 | August 11, 2025 | August 17, 2025 |
| Week 34 | August 18, 2025 | August 24, 2025 |
| Week 35 | August 25, 2025 | August 31, 2025 |
| Week 36 | September 1, 2025 | September 7, 2025 |
| Week 37 | September 8, 2025 | September 14, 2025 |
| Week 38 | September 15, 2025 | September 21, 2025 |
| Week 39 | September 22, 2025 | September 28, 2025 |
| Week 40 | September 29, 2025 | October 5, 2025 |
| Week 41 | October 6, 2025 | October 12, 2025 |
| Week 42 | October 13, 2025 | October 19, 2025 |
| Week 43 | October 20, 2025 | October 26, 2025 |
| Week 44 | October 27, 2025 | November 2, 2025 |
| Week 45 | November 3, 2025 | November 9, 2025 |
| Week 46 | November 10, 2025 | November 16, 2025 |
| Week 47 | November 17, 2025 | November 23, 2025 |
| Week 48 | November 24, 2025 | November 30, 2025 |
| Week 49 | December 1, 2025 | December 7, 2025 |
| Week 50 | December 8, 2025 | December 14, 2025 |
| Week 51 | December 15, 2025 | December 21, 2025 |
| Week 52 | December 22, 2025 | December 28, 2025 |
Dates are calendar dates under ISO 8601 week dating. A week belongs to the ISO year that contains its Thursday, which is why the first row can start in late December of the previous calendar year and the last row can end in early January of the next one.
About the 2025 ISO year
ISO 2025 opens early: its week 1 begins on Monday, December 30, 2024, because the Thursday of that week is January 2, 2025. It is a 52-week year, and it hands over cleanly — ISO 2026 starts the very next day, Monday, December 29, 2025. ISO years tile without gaps or overlaps; every Monday on the calendar opens exactly one numbered week.