๐ Week of Month Calculator
Counts in blocks of 7 days, with the week containing the 1st of the month as week 1.
Enter a date to calculate which week of the month it falls in (counting from the 1st), and which occurrence of that weekday it is โ e.g. "the 3rd Monday".
How to use
- Enter a date.
- The week of the month and the weekday occurrence are shown automatically.
How the calculation works
Enter a date to see which week of the month it falls in and how to say it as โthe nth weekday of the monthโ. Counting: days 1โ7 are week 1, 8โ14 week 2, 15โ21 week 3, 22โ28 week 4 and 29โ31 week 5 (the day divided by 7, rounded up) This always matches how many times that weekday has occurred in the month. If September 15 is a Tuesday, it is in week 3 and is โthe third Tuesday of Septemberโ. That makes it easy to check whether a date matches a rule such as โevery third Tuesdayโ.
Worked example
Saturday, September 19, 2026 โ week 3 (the third Saturday of September) Tuesday, September 1, 2026 โ week 1 (the first Tuesday of September) Tuesday, September 29, 2026 โ week 5 (the fifth Tuesday of September) Monday, October 12, 2026 โ week 2 (the second Monday of October, Japanโs Sports Day)
Things to be aware of
- This can differ from counting rows on a calendar (weeks starting Monday or Sunday). In a month starting on a Saturday, the Monday in the second calendar row is the 3rd, but here it is still week 1.
- For week numbers across the whole year (ISO weeks), use the Week Number Calculator.
- Week 5 contains only the 29th and later.
FAQ
How is the "week of month" counted?
The week containing the 1st of the month is week 1: days 1-7 are week 1, days 8-14 are week 2, and so on in blocks of 7 (the day-of-month divided by 7, rounded up).
How does this relate to something like "the 3rd Monday"?
This tool's "week of month" always matches how many times that weekday has occurred in the month so far โ e.g. it directly tells you it's the "3rd Monday". Handy for checking recurring rules like "team meeting on the 2nd Tuesday of every month".
Is this different from ISO week numbers?
Yes. This tool calculates the week within the month, counting from the 1st. For week numbers spanning the whole year (ISO 8601 style), use the Week Number Calculator instead.