How many weeks are in a year?
Most years have 52 full weeks and 1 extra day. Leap years have 52 weeks and 2 days.

What is the ISO week?
It's an international standard where each week starts on Monday, and the first week contains the first Thursday of the year.

How can I find the current week number?
You can use our tools to see the current ISO week number instantly.

How do I calculate weeks between dates?
Use the calculator above to select a start and end date. It will tell you how many full and partial weeks are between them.