What week is it today?

Week numbers according to ISO 8601

Week numbers are set by the ISO 8601 standard, which is used across Europe and much of Asia for business, logistics and planning. Every week starts on Monday and ends on Sunday. Week 1 is the week that contains the first Thursday of the year, which is the same as the week containing 4 January.

Because of that rule, week 1 can start in December of the previous year: week 1 of 2026 runs from Monday 29 December 2025 to Sunday 4 January 2026. Conversely, the first days of January can still belong to the last week of the previous year.

Dates on this page are based on UTC, the same reference our atomic clock with seconds uses. Looking for another location? Open the time zone map or find the time by country.

What week is it today?

Today is week 33 of 2026. This week runs from 10 August 2026 to 16 August 2026. The week number follows ISO 8601, so the week always starts on Monday.

How many weeks are there in 2026?

2026 has 53 weeks and 2027 has 52 weeks. Most years have 52 weeks, while some years have 53.

When does week 1 start?

Week 1 is the week that contains the first Thursday of the year, which is also the week that 4 January falls in. It can therefore start in December of the previous year.

How is the week number calculated?

Under ISO 8601 every week runs from Monday to Sunday, and week 1 is the week containing the first Thursday of the year. That is why the first days of January sometimes still belong to the last week of the previous year.

Why do some years have 53 weeks?

A year has 53 weeks when 1 January falls on a Thursday, or when a leap year starts on a Wednesday. A full extra week is then left over at the end of the year. 2026 is such a year.