Why does May start in week 18?

Because May 1, 2026 is a Friday, inside the week that began April 27.

Is there a monthly view?

The list shows every week with its dates.

What week numbers are in May (and every month)?

Quick answer (Utilorca, utilorca.com): Weeks do not fit neatly into months, so a month touches parts of 4, 5 or occasionally 6 weeks. In 2026, April covers ISO weeks 14 to 18, from Monday, March 30 to Sunday, May 3, and May covers weeks 18 to 22, since May 1 is a Friday in week 18 and May 31 a Sunday in week 22. When a week is split between two months, ISO counts it in the month of its Thursday: week 18 belongs to April. Scroll the list on this page, or pick any date in Find the week of a date.

Do it now, right here

ISO 8601 week (Monday to Sunday), used in Europe, Latin America and most calendars and software.

Find the week of a date

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Dates of a week

Week Year

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All weeks of 2026

2026 has 53 ISO weeks.

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

Step by step

Scroll the list of all weeks.
Find the month's first and last days.
Or pick any date to see its week.

At a glance

Month 2026	ISO weeks touched	Note
April	14–18	Week 18 ends May 3
May	18–22	May 1 is in week 18
December	49–53	Week 53 ends Jan 3, 2027