Week 51 2027: December 20–26, 2027
Week 51 starts on Monday, December 20, 2027 and ends on Sunday, December 26, 2027.
Quick answer
Week 51 of 2027 is the seven-day ISO week from December 20, 2027 to December 26, 2027. ISO weeks always run from Monday to Sunday.
Use week 51 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 51 of 2027?
The dates are December 20, 2027 through December 26, 2027.
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 51 of 2027 (Dec 20–Dec 26, 2027)” so the week-year and date range are both clear.