ISO week

Week 51 of 2026

2026-W51December 14–20, 2026Monday through Sunday

Mon14December Tue15December Wed16December Thu17December Fri18December Sat19December Sun20December

ISO notation2026-W51

Start12-14-2026

End12-20-2026

ISO weeks in year53

All seven days in Week 51

MondayDecember 14, 2026 TuesdayDecember 15, 2026 WednesdayDecember 16, 2026 ThursdayDecember 17, 2026 FridayDecember 18, 2026 SaturdayDecember 19, 2026 SundayDecember 20, 2026

Week 51 context

ISO Week 51 of 2026 runs from December 14, 2026 through December 20, 2026. ISO weeks always contain seven days and start on Monday.

Nearby weeks

Week 48 Week 49 Week 50 Week 51 Week 52 Week 53

All weeks in 2026 →