When is week 1?
In 2026, week 1 runs from Monday, December 29, 2025 to Sunday, January 4, 2026.
It ended 271 days ago.
Week 1 in other years
| Year | Starts | Ends |
|---|---|---|
| 2025 | Mon, Dec 30, 2024 | Sun, Jan 5, 2025 |
| 2026 | Mon, Dec 29, 2025 | Sun, Jan 4, 2026 |
| 2027 | Mon, Jan 4, 2027 | Sun, Jan 10, 2027 |
| 2028 | Mon, Jan 3, 2028 | Sun, Jan 9, 2028 |
Related
Questions & answers
What dates are in week 1?
In 2026, week 1 is December 29, 2025 to January 4, 2026.
How are week numbers counted?
We use ISO 8601 week numbers: weeks start on Monday, and week 1 is the week that contains the first Thursday of the year.