What week is it?
What week is it today by the ISO count, which Britain and most of Europe use, and by the US count. You'll also find this week's dates and how many weeks are left in the year.
What week is it?
-- ISO week, Monday to Sunday
-- US week, Sunday to Saturday
-- weeks left this year.
ISO and US week numbers
What week of the year it is, twice
Every date gets two week numbers here, the ISO one and the US one, and they can be a week apart.
- ISO weeks run Monday to Sunday, and week 1 holds the year’s first Thursday.
- US weeks run Sunday to Saturday, and week 1 holds January 1, even if only one day of it is in the new year.
Why “what week is it” depends on where you are
Countries disagree on which day a week starts and which week is week 1. The week starts on Sunday in the US, Canada, Japan, India, Brazil and Mexico, and on Monday in the UK. The UK also takes the ISO rule for week 1, so a plan that only says “week 14” should say which count it means.
Whichever day your week starts, work due EOW is due on Friday. Starting on Sunday doesn’t buy you an extra day. The how long until Friday clock counts down the time you do have.
Week numbers in Excel
Excel’s WEEKNUM gives you the US week number unless you add a second number to the formula.
| Excel formula | Week it gives |
|---|---|
| WEEKNUM(date, 21) | ISO week |
| ISOWEEKNUM(date) | ISO week, in current Excel |
| WEEKNUM(date, 2) | Weeks that start on Monday, but week 1 still holds January 1 |
When a year has 53 weeks
Years with 53 weeks
An ISO year has 53 weeks when it starts on a Thursday, or on a Wednesday in a leap year.
| Count and length | Years |
|---|---|
| ISO, 53 weeks, from 2020 to 2040 | 2020, 2026, 2032 and 2037 |
| US, 53 weeks | Most years |
| US, 54 weeks | A leap year that starts on a Saturday, like 2028. Its week 54 is December 31 alone. |
Retailers count their year in whole weeks as well, so every few years they need a 53rd one. That extra week shifts what quarter it is for them by a week. If 53 weeks sounds like a long year at work, the other work clocks count down to 5 pm and to Friday. One goes all the way to the day you retire.
This year's week numbers
Week number calendar for 2026
ISO weeks, each from its Monday to its Sunday.
- 1 Dec 29 to Jan 4
- 2 Jan 5 to Jan 11
- 3 Jan 12 to Jan 18
- 4 Jan 19 to Jan 25
- 5 Jan 26 to Feb 1
- 6 Feb 2 to Feb 8
- 7 Feb 9 to Feb 15
- 8 Feb 16 to Feb 22
- 9 Feb 23 to Mar 1
- 10 Mar 2 to Mar 8
- 11 Mar 9 to Mar 15
- 12 Mar 16 to Mar 22
- 13 Mar 23 to Mar 29
- 14 Mar 30 to Apr 5
- 15 Apr 6 to Apr 12
- 16 Apr 13 to Apr 19
- 17 Apr 20 to Apr 26
- 18 Apr 27 to May 3
- 19 May 4 to May 10
- 20 May 11 to May 17
- 21 May 18 to May 24
- 22 May 25 to May 31
- 23 Jun 1 to Jun 7
- 24 Jun 8 to Jun 14
- 25 Jun 15 to Jun 21
- 26 Jun 22 to Jun 28
- 27 Jun 29 to Jul 5
- 28 Jul 6 to Jul 12
- 29 Jul 13 to Jul 19
- 30 Jul 20 to Jul 26
- 31 Jul 27 to Aug 2
- 32 Aug 3 to Aug 9
- 33 Aug 10 to Aug 16
- 34 Aug 17 to Aug 23
- 35 Aug 24 to Aug 30
- 36 Aug 31 to Sep 6
- 37 Sep 7 to Sep 13
- 38 Sep 14 to Sep 20
- 39 Sep 21 to Sep 27
- 40 Sep 28 to Oct 4
- 41 Oct 5 to Oct 11
- 42 Oct 12 to Oct 18
- 43 Oct 19 to Oct 25
- 44 Oct 26 to Nov 1
- 45 Nov 2 to Nov 8
- 46 Nov 9 to Nov 15
- 47 Nov 16 to Nov 22
- 48 Nov 23 to Nov 29
- 49 Nov 30 to Dec 6
- 50 Dec 7 to Dec 13
- 51 Dec 14 to Dec 20
- 52 Dec 21 to Dec 27
- 53 Dec 28 to Jan 3
Questions about week numbers
What week are we out of 52?
Out of 52 in most years. 2026 is one of the long ones, with an ISO week 53. In a 52-week year, you're halfway through when week 26 ends.
Does week 53 exist?
Yes. In 2026, ISO week 53 runs from Monday, December 28 to Sunday, January 3, 2027, so New Year's Day 2027 falls in week 53 of 2026.
Why does 2026 have 53 weeks?
Because January 1, 2026 was a Thursday. ISO gives each week to the year its Thursday falls in, and a year that starts on a Thursday has 53 Thursdays.
What week of the year is this?
For the ISO number, count from the week with the year's first Thursday in it. The US number counts from the week with January 1 in it. In 2026, ISO week 1 began on Monday, December 29, 2025, and US week 1 ran only three days, from Thursday, January 1 to Saturday, January 3.
What week is it now in Australia?
Australia starts its weeks on Monday but can count week 1 from January 1, as the US does. So an Australian calendar can show a week number one higher than the ISO count.
Is Monday the start of the week in the UK?
Yes. The UK starts its week on Monday and takes the ISO rule for week 1, the week that holds the year's first Thursday. The US starts its week on Sunday.