ISO week details

Week 21 1264: May 19–25, 1264

Week 21 starts on Monday, May 19, 1264 and ends on Sunday, May 25, 1264.

Week21
ISO year1264
StartMay 19
EndMay 25

Quick answer

Week 21 of 1264 is the seven-day ISO week from May 19, 1264 to May 25, 1264. ISO weeks always run from Monday to Sunday.

Dates for each day of this week

  • Monday: May 19, 1264
  • Tuesday: May 20, 1264
  • Wednesday: May 21, 1264
  • Thursday: May 22, 1264
  • Friday: May 23, 1264
  • Saturday: May 24, 1264
  • Sunday: May 25, 1264

Plan this exact week →

The planner opens with this Monday selected. Public holidays depend on your country and are not subtracted automatically.

Check the current work week

Need today’s week instead? Open the current work week dashboard for the live ISO week number, Monday-to-Sunday range, business days left and Friday planning date.

Use week 21 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 21 of 1264?

The dates are May 19, 1264 through May 25, 1264.

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 21 of 1264 (May 19–May 25, 1264)” so the week-year and date range are both clear.