Dates of Each Week Number
This week is ISO week 42 of 2026, Monday October 12, 2026 to Sunday October 18, 2026. In Excel or Google Sheets, the formula =ISOWEEKNUM(TODAY()) gives the same number. Pick a week below to see its seven dates, from Monday to Sunday, the next time it comes round.
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Questions
What week number is it now?
See week numbers by year or the week number calculator for today's ISO and US week.
When does an ISO week start?
On Monday. Week 1 is the week with the year's first Thursday, so it can start in late December.
Does every year have a week 53?
No, only years that start on a Thursday, or leap years that start on a Wednesday. The table on the week numbers page shows which years they are.