Calendar With Week Numbers – Any Month or Year
See any month or a full year with ISO week numbers, today’s date highlighted and weekends marked. Switch between Monday and Sunday as the first day.
Pick a year and a month (or “Whole year”). The left column shows the ISO week number of each row; week 1 is the week that contains the first Thursday of January. A normal year has 365 days and 52 weeks; some years have 53 ISO weeks.
How to use the Calendar with Week Numbers
- Choose the year and month, or switch the view to the whole year.
- Choose whether weeks start on Monday (Europe, ISO) or Sunday (US).
- Use ‹ and › to move between months or years. Print with Ctrl+P / Cmd+P.
ISO week numbers
Under ISO 8601, weeks start on Monday and week 1 is the week with the first Thursday of the year. That is why 1 January can belong to week 52 or 53 of the previous year. Years starting on a Thursday (and leap years starting on a Wednesday) have 53 weeks — 2026 is one of them.
How many days and weeks in a year?
| Period | Days | Weeks |
|---|---|---|
| Normal year | 365 | 52 weeks + 1 day |
| Leap year | 366 | 52 weeks + 2 days |
| 6 months | 181–184 | about 26 |
| 1 month | 28–31 | about 4.3 |
Days in each month
“Thirty days has September, April, June and November; all the rest have thirty-one, except February alone” — which has 28 days, or 29 in a leap year. Leap years are divisible by 4, except century years not divisible by 400.
Related tools: Today's Date, Days Between Dates Calculator and Days From Today Calculator.
Frequently asked questions
What week number is it today?
Today is highlighted in the calendar; its week number is in the left column. The Today’s date page also shows it.
How many weeks are in a year?
52 weeks and 1 day (2 in a leap year). In the ISO system a year has 52 or 53 weeks.
Does the week start on Monday or Sunday?
Europe and ISO 8601 use Monday; the US and Canada usually use Sunday. You can switch above.
Is 2028 a leap year?
Yes. 2028 is divisible by 4 and is a leap year with 366 days.
Can I print the calendar?
Yes. Choose the month or year view and print the page with Ctrl+P (Cmd+P on a Mac).
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