Week 12 2025: March 17–23, 2025
Week 12 starts on Monday, March 17, 2025 and ends on Sunday, March 23, 2025.
Quick answer
Week 12 of 2025 is the seven-day ISO week from March 17, 2025 to March 23, 2025. ISO weeks always run from Monday to Sunday.
Use week 12 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.
Weeks around week 12
Browse priority week calendars
Continue with a planning tool
FAQ
What are the dates for week 12 of 2025?
The dates are March 17, 2025 through March 23, 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 12 of 2025 (Mar 17–Mar 23, 2025)” so the week-year and date range are both clear.