ISO week details

Week 1 1809: January 2–8, 1809

Week 1 starts on Monday, January 2, 1809 and ends on Sunday, January 8, 1809.

Week1
ISO year1809
StartJan 2
EndJan 8

Quick answer

Week 1 of 1809 is the seven-day ISO week from January 2, 1809 to January 8, 1809. 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.

FAQ

What are the dates for week 1 of 1809?

The dates are January 2, 1809 through January 8, 1809.

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 1809 (Jan 2–Jan 8, 1809)” so the week-year and date range are both clear.