What dates are in week 1 of 2026?

Week 1 runs from December 29, 2025 through January 4, 2026.

How many weekdays are in week 1?

There are five Monday-to-Friday weekdays before country-specific public holidays are excluded.

Exact ISO week dates

Week 1 of 2026

Week 1 of 2026 runs from Monday, December 29, to Sunday, January 4. See every date, weekday count and adjacent ISO weeks.

ISO week 1December 29–January 4, 2026Monday through Sunday · 5 weekdays · 2 weekend days

Past

Dates in week 1

Day	Date	Type
Monday	December 29, 2025	Weekday
Tuesday	December 30, 2025	Weekday
Wednesday	December 31, 2025	Weekday
Thursday	January 1, 2026	Weekday
Friday	January 2, 2026	Weekday
Saturday	January 3, 2026	Weekend
Sunday	January 4, 2026	Weekend

About week 1 of 2026

Week 1 of 2026 runs from Monday, December 29 through Sunday, January 4. It spans December and January and contains five standard Monday-to-Friday weekdays.

Public holidays are country-specific and are not removed from this basic weekday count. Use the working-days calculator when holidays need to be excluded.