Week 1 2025: December 30–5, 2025
Week 1 starts on Monday, December 30, 2024 and ends on Sunday, January 5, 2025.
Quick answer
Week 1 of 2025 is the seven-day ISO week from December 30, 2024 to January 5, 2025. ISO weeks always run from Monday to Sunday.
Use week 1 in professional planning
This permanent week reference can be used in project plans, payroll notes, weekly reports, production schedules and deadline documents. Share the week number together with the ISO year and exact date range to avoid ambiguity around New Year.
For calculations that span more than one week, use the weeks between dates calculator. For work schedules, compare the same range with the business days calculator or open the project timeline calculator.
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FAQ
What are the dates for week 1 of 2025?
The dates are December 30, 2024 through January 5, 2025.
What day does this week start?
It starts on Monday.
What day does this week end?
It ends on Sunday.
How should I write this week in a report?
Use “ISO week 1 of 2025 (Dec 30–Jan 5, 2025)” so the week-year and date range are both clear.