Week numbers

2025 has 52 ISO weeks, Monday to Sunday

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

How week numbers work

These follow the ISO 8601 standard used across Europe and in most business software: weeks run Monday to Sunday, and week 1 is the week containing the year's first Thursday. That's why a year has 52 or 53 weeks, and why the last days of December can belong to week 1 of the next year.

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