What week is it?

How many weeks are left in 2026?

After today there are 81 days left in 2026, which is 11 weeks and 4 days. The last ISO week of the year is week 53, which runs into the first days of January. Week counts are handy for year-end planning: the number of paychecks, workouts or savings deposits left, or how many weekends there are before the holidays. For day counts, see the day of the year page or days until Christmas.

ISO week numbers vs US week numbers

There are two common ways to number weeks, and they can disagree by one:

• ISO 8601, used in Europe, in most business and payroll software and in many planners. Weeks run Monday to Sunday, and week 1 is the week that contains the year’s first Thursday. Because of that rule, January 1–3 can belong to the last week of the previous year, and December 29–31 to week 1 of the next.
• US calendars and Excel’s default WEEKNUM start weeks on Sunday and call the week that contains January 1 week 1, however short it is. That makes the last week of December week 53 in most years, and sometimes week 54.

When a supplier, school or employer gives you a week number, ask which system it uses. Most international business deadlines mean ISO weeks.

Does 2026 have 52 or 53 weeks?

A year is 52 weeks plus one day, or plus two days in a leap year, so every five or six years the extra days add up to a 53rd ISO week. That happens when a year starts on a Thursday, or on a Wednesday in a leap year. 2026 has 53 ISO weeks, ending on Sun, Jan 3, 2027; the next year with 53 is 2032. Payroll notices the same drift: a weekly schedule has 53 paydays in some years, and a biweekly one 27.

Week numbers in software

• Excel and Google Sheets: =ISOWEEKNUM(A1) for the ISO week; =WEEKNUM(A1) for weeks starting Sunday, or =WEEKNUM(A1,2) for weeks starting Monday with January 1 still in week 1.
• Mac and Linux terminal: date +%V prints the ISO week. date +%U counts Sunday weeks but numbers the days before the first Sunday as week 00, so it is often one lower than WEEKNUM.
• Python: date.today().isocalendar()[1] gives the ISO week.
• SQL: EXTRACT(WEEK FROM d) in PostgreSQL and DATEPART(iso_week, d) in SQL Server return the ISO week. MySQL’s WEEK(d, 3) does the same.

ISO weeks of 2026

Each ISO week runs from Monday to Sunday. Week 1 of 2026 starts on Mon, Dec 29, 2025.