Week 1 in 2025
Week 1 of 2025 spans the turn of the year: it begins on December 30, 2024 and ends on January 5, 2025.
Weeks since this week: 93
Week 1 of 2025 at a glance
| Starts (Monday) | December 30, 2024 |
|---|---|
| Ends (Sunday) | January 5, 2025 |
| US week (Sunday to Saturday) | 1 (December 29, 2024) |
| Month | December / January |
| Quarter | Q1 |
| Year completed at the end of this week | 1.4% |
| Weeks left in 2025 after this week | 51 |
| Weeks in 2025 | 52 |
| Even or odd week | Odd |
Calendar for December 2025
Download Calendar in printable A4 PDF
(US version) (EU/ISO Version)
All Weeks in 2025:
Past & Future Week Number 1:
US and ISO week numbers
In the US system, where weeks start on Sunday and week 1 is the week that contains 1 January, this is week 1 of 2025. It runs from December 29, 2024 to January 4, 2025.
Even and odd weeks
Week 1 is an odd week. Even and odd week numbers are used for alternating schedules such as shift rotas, school timetables, custody arrangements and waste collection.
Week 1 in other years
| From | To | |
|---|---|---|
| Week 1 in 2023 | January 2, 2023 | January 8, 2023 |
| Week 1 in 2024 | January 1, 2024 | January 7, 2024 |
| Week 1 in 2026 | December 29, 2025 | January 4, 2026 |
| Week 1 in 2027 | January 4, 2027 | January 10, 2027 |
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 2025 began on December 30, 2024. 2025 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.
Find the week number of a date
Frequently Asked Questions (FAQ)
When does week 1 of 2025 start and end?
Week 1 of 2025 starts on December 30, 2024 and ends on January 5, 2025 (ISO 8601, Monday to Sunday).
Which month is week 1 of 2025 in?
Week 1 of 2025 starts in December and ends in January.
What dates are in week 1 of 2025?
December 30, 2024, December 31, 2024, January 1, 2025, January 2, 2025, January 3, 2025, January 4, 2025, and January 5, 2025
How many weeks does 2025 have?
2025 has 52 ISO weeks.
Is week 1 an even or odd week?
Week 1 is an odd week.
What is the US week number for this week?
In the US system, where weeks start on Sunday and week 1 is the week that contains 1 January, this is week 1 of 2025. It runs from December 29, 2024 to January 4, 2025.