Week Numbers in Norway 2026 and 2027 (Ukenummer)

Norwegians use week numbers (ukenummer) all the time: in school calendars, staff rotas, delivery dates, building schedules and meeting invitations, where "we will deliver in week 42" is normal. This calculator shows the week number of today or of any date, the dates a given week covers, and every week of a year. Today's week is worked out in your browser, so it is always current.

How the ISO 8601 week numbering works

• A week starts on Monday and ends on Sunday.
• Week 1 is the week that contains the first Thursday of the year. That is the same as the week that contains 4 January, or the first week with at least four days in the new year.
• A week belongs to the year that holds its Thursday. That is why the first days of January can be in week 52 or 53 of the previous year, and the last days of December can be in week 1 of the next.

Example: Tuesday, 23 June 2026 is in week 26, which runs 22 Jun to 28 Jun, leaving 27 weeks of 2026. Around New Year it is less obvious. Thursday, 31 December 2026 is in week 53 of 2026, Friday, 1 January 2027 is in week 53 of 2026 too, and week 1 of 2027 only starts on Monday, 4 January 2027.

Years with 53 weeks

A normal year is 52 weeks and one day, and a leap year is 52 weeks and two days. The spare days add up, and about every fifth or sixth year gets a week 53. That happens when the year starts on a Thursday, or when a leap year starts on a Wednesday. Years with week 53 between 2015 and 2045: 2015, 2020, 2026, 2032, 2037, 2043. So 2026 has 53 weeks and 2027 has 52. If you plan rotas, budgets or contracts by week number, check whether the year has a week 53.

Week numbers of the public holidays, 2026 and 2027

All holidays, squeeze days and long weekends are on the Norway public holidays calculator.

All week numbers, 2026 and 2027

Other week systems, and Excel

Some countries and programs start the week on Sunday and call the week with 1 January week 1. Microsoft calls this system 1 and it is the default in Excel's WEEKNUM function. Then a date can have a different week number from the Norwegian one. When you agree a delivery or a holiday week with someone in Norway, use the ISO number. In Excel, use ISOWEEKNUM, or WEEKNUM with return type 21. Company fiscal weeks are a separate matter and can start on other days.

If you have just moved to Norway

Expect to be asked for a week number: "week 27" on a job notice or a delivery slip means Monday to Sunday of that ISO week. Do not use a calendar that starts on Sunday for planning around New Year, and remember that "week 1" can begin in December. Work out how many working days a period has with the Norway working days calculator, and count notice with the notice period calculator, which runs in calendar days rather than weeks.

What this calculator does not cover

• Week counts in other contexts, such as weeks of pregnancy or a company's fiscal calendar. This page is only the calendar week (ISO 8601).
• Public holidays inside a week are only marked for Norway, and only by the dates in the Holidays Acts.
• Dates before 1900 or after 2100.