What Week Is It?

Today's week number, the day of the year and days left in the year. Look up the week of any date or browse this year's full week table.

Find the week number of any date

2026 week numbers

1Dec 29 – Jan 4
2Jan 5 – Jan 11
3Jan 12 – Jan 18
4Jan 19 – Jan 25
5Jan 26 – Feb 1
6Feb 2 – Feb 8
7Feb 9 – Feb 15
8Feb 16 – Feb 22
9Feb 23 – Mar 1
10Mar 2 – Mar 8
11Mar 9 – Mar 15
12Mar 16 – Mar 22
13Mar 23 – Mar 29
14Mar 30 – Apr 5
15Apr 6 – Apr 12
16Apr 13 – Apr 19
17Apr 20 – Apr 26
18Apr 27 – May 3
19May 4 – May 10
20May 11 – May 17
21May 18 – May 24
22May 25 – May 31
23Jun 1 – Jun 7
24Jun 8 – Jun 14
25Jun 15 – Jun 21
26Jun 22 – Jun 28
27Jun 29 – Jul 5
28Jul 6 – Jul 12
29Jul 13 – Jul 19
30Jul 20 – Jul 26
31Jul 27 – Aug 2
32Aug 3 – Aug 9
33Aug 10 – Aug 16
34Aug 17 – Aug 23
35Aug 24 – Aug 30
36Aug 31 – Sep 6
37Sep 7 – Sep 13
38Sep 14 – Sep 20
39Sep 21 – Sep 27
40Sep 28 – Oct 4
41Oct 5 – Oct 11
42Oct 12 – Oct 18
43Oct 19 – Oct 25
44Oct 26 – Nov 1
45Nov 2 – Nov 8
46Nov 9 – Nov 15
47Nov 16 – Nov 22
48Nov 23 – Nov 29
49Nov 30 – Dec 6
50Dec 7 – Dec 13
51Dec 14 – Dec 20
52Dec 21 – Dec 27
53Dec 28 – Jan 3

ISO 8601 week rules

ISO 8601 weeks run Monday to Sunday and January 4 is always in week 1; this is the system used across Europe and in most planning tools. US calendars often number weeks from the Sunday week containing January 1 instead. Week 40 of 2026 started on Monday, September 28.

Frequently Asked Questions

What week number is it today?
When this page was last updated (October 1, 2026), it was ISO week 40 of 2026. The box at the top always shows the live week.

What is the difference between ISO and US week numbers?
ISO 8601 weeks start on Monday and week 1 is the week with the year's first Thursday. The US system starts weeks on Sunday and week 1 is the week containing January 1, so the two can differ by one.

How many weeks are in a year?
A year has 52 or 53 ISO weeks; 2026 has 53. Years starting on a Thursday, and leap years starting on a Wednesday, have 53.

Which week system does Excel use?
ISOWEEKNUM() returns the ISO week. WEEKNUM() uses the US system by default (Sunday start, week 1 contains January 1).