What week is it?

The current ISO week number, live from your device's date, plus a date-to-week converter and the full week tables for 2026 and 2027.

This week is

How week numbers work

Week numbers here follow ISO 8601, the standard used in Europe, in most businesses and by most software: weeks start on Monday, and week 1 is the week that contains the first Thursday of the year (equivalently, 4 January). A year has 52 weeks, or 53 when it starts on a Thursday, or on a Wednesday in a leap year. The first days of January can therefore belong to week 52 or 53 of the previous year, and the last days of December to week 1 of the next.

The US convention, where week 1 is the week containing 1 January and weeks start on Sunday, gives numbers that can differ by one; the counter above shows the ISO value.

Week numbers 2026

Week	Monday	Sunday
1	Mon 29 Dec	Sun 04 Jan
2	Mon 05 Jan	Sun 11 Jan
3	Mon 12 Jan	Sun 18 Jan
4	Mon 19 Jan	Sun 25 Jan
5	Mon 26 Jan	Sun 01 Feb
6	Mon 02 Feb	Sun 08 Feb
7	Mon 09 Feb	Sun 15 Feb
8	Mon 16 Feb	Sun 22 Feb
9	Mon 23 Feb	Sun 01 Mar
10	Mon 02 Mar	Sun 08 Mar
11	Mon 09 Mar	Sun 15 Mar
12	Mon 16 Mar	Sun 22 Mar
13	Mon 23 Mar	Sun 29 Mar
14	Mon 30 Mar	Sun 05 Apr
15	Mon 06 Apr	Sun 12 Apr
16	Mon 13 Apr	Sun 19 Apr
17	Mon 20 Apr	Sun 26 Apr
18	Mon 27 Apr	Sun 03 May
19	Mon 04 May	Sun 10 May
20	Mon 11 May	Sun 17 May
21	Mon 18 May	Sun 24 May
22	Mon 25 May	Sun 31 May
23	Mon 01 Jun	Sun 07 Jun
24	Mon 08 Jun	Sun 14 Jun
25	Mon 15 Jun	Sun 21 Jun
26	Mon 22 Jun	Sun 28 Jun
27	Mon 29 Jun	Sun 05 Jul
28	Mon 06 Jul	Sun 12 Jul
29	Mon 13 Jul	Sun 19 Jul
30	Mon 20 Jul	Sun 26 Jul
31	Mon 27 Jul	Sun 02 Aug
32	Mon 03 Aug	Sun 09 Aug
33	Mon 10 Aug	Sun 16 Aug
34	Mon 17 Aug	Sun 23 Aug
35	Mon 24 Aug	Sun 30 Aug
36	Mon 31 Aug	Sun 06 Sep
37	Mon 07 Sep	Sun 13 Sep
38	Mon 14 Sep	Sun 20 Sep
39	Mon 21 Sep	Sun 27 Sep
40	Mon 28 Sep	Sun 04 Oct
41	Mon 05 Oct	Sun 11 Oct
42	Mon 12 Oct	Sun 18 Oct
43	Mon 19 Oct	Sun 25 Oct
44	Mon 26 Oct	Sun 01 Nov
45	Mon 02 Nov	Sun 08 Nov
46	Mon 09 Nov	Sun 15 Nov
47	Mon 16 Nov	Sun 22 Nov
48	Mon 23 Nov	Sun 29 Nov
49	Mon 30 Nov	Sun 06 Dec
50	Mon 07 Dec	Sun 13 Dec
51	Mon 14 Dec	Sun 20 Dec
52	Mon 21 Dec	Sun 27 Dec
53	Mon 28 Dec	Sun 03 Jan

Week numbers 2027

Week	Monday	Sunday
1	Mon 04 Jan	Sun 10 Jan
2	Mon 11 Jan	Sun 17 Jan
3	Mon 18 Jan	Sun 24 Jan
4	Mon 25 Jan	Sun 31 Jan
5	Mon 01 Feb	Sun 07 Feb
6	Mon 08 Feb	Sun 14 Feb
7	Mon 15 Feb	Sun 21 Feb
8	Mon 22 Feb	Sun 28 Feb
9	Mon 01 Mar	Sun 07 Mar
10	Mon 08 Mar	Sun 14 Mar
11	Mon 15 Mar	Sun 21 Mar
12	Mon 22 Mar	Sun 28 Mar
13	Mon 29 Mar	Sun 04 Apr
14	Mon 05 Apr	Sun 11 Apr
15	Mon 12 Apr	Sun 18 Apr
16	Mon 19 Apr	Sun 25 Apr
17	Mon 26 Apr	Sun 02 May
18	Mon 03 May	Sun 09 May
19	Mon 10 May	Sun 16 May
20	Mon 17 May	Sun 23 May
21	Mon 24 May	Sun 30 May
22	Mon 31 May	Sun 06 Jun
23	Mon 07 Jun	Sun 13 Jun
24	Mon 14 Jun	Sun 20 Jun
25	Mon 21 Jun	Sun 27 Jun
26	Mon 28 Jun	Sun 04 Jul
27	Mon 05 Jul	Sun 11 Jul
28	Mon 12 Jul	Sun 18 Jul
29	Mon 19 Jul	Sun 25 Jul
30	Mon 26 Jul	Sun 01 Aug
31	Mon 02 Aug	Sun 08 Aug
32	Mon 09 Aug	Sun 15 Aug
33	Mon 16 Aug	Sun 22 Aug
34	Mon 23 Aug	Sun 29 Aug
35	Mon 30 Aug	Sun 05 Sep
36	Mon 06 Sep	Sun 12 Sep
37	Mon 13 Sep	Sun 19 Sep
38	Mon 20 Sep	Sun 26 Sep
39	Mon 27 Sep	Sun 03 Oct
40	Mon 04 Oct	Sun 10 Oct
41	Mon 11 Oct	Sun 17 Oct
42	Mon 18 Oct	Sun 24 Oct
43	Mon 25 Oct	Sun 31 Oct
44	Mon 01 Nov	Sun 07 Nov
45	Mon 08 Nov	Sun 14 Nov
46	Mon 15 Nov	Sun 21 Nov
47	Mon 22 Nov	Sun 28 Nov
48	Mon 29 Nov	Sun 05 Dec
49	Mon 06 Dec	Sun 12 Dec
50	Mon 13 Dec	Sun 19 Dec
51	Mon 20 Dec	Sun 26 Dec
52	Mon 27 Dec	Sun 02 Jan

Questions

Will the alarm ring if I close the tab or the laptop?

No. No website can ring after the browser is closed or the computer sleeps. Keep this tab open, plug in, and the clock keeps the screen awake for you. The Ready-to-ring check under the clock shows what is set up correctly.

Does it work on my phone?

Yes on Android while the tab is open (behind other tabs is fine). On iPhone the page must stay in the foreground because Safari does not let web pages play sound from the background. Add it to the Home Screen for a full-screen bedside clock.

Is it loud enough for heavy sleepers?

Pick Loud buzzer or Siren, set the volume slider to full, and switch on the sums-to-stop option in Settings so the alarm cannot be dismissed half asleep. The sunrise light brightens the screen before the alarm too.

Can I use my own sound?

Yes. In Settings, choose an MP3, WAV or OGG file. It is stored in this browser only and never uploaded. There are also 60 built-in sounds, from a twin-bell alarm clock and a rooster to an air horn and a music box, on the sounds page.

What do the sleep sounds do?

Rain, brown noise, white noise, fan and ocean are generated in the browser and play until the alarm, then fade out as it rings. They keep the tab active through the night.

Does it need an internet connection?

Only to load the page the first time. Alarms, sounds, the sleep calculator and the sunrise math all run on your device, and the page works offline once it has been opened.

Is anything stored or sent?

Alarms and settings are saved in your browser's local storage. Nothing is sent to a server, and there is no account.

How many weeks are left in the year?

The line under the counter says how many ISO weeks remain, counted from this week to the last week of the year.

Why does my calendar show a different week number?

Outlook and Google Calendar can be set to either the ISO rule (weeks start Monday, week 1 contains 4 January) or the US rule (weeks start Sunday, week 1 contains 1 January). Check the calendar's week-number setting.

Which year does 1 January belong to?

In the ISO system it can belong to the last week of the previous year. The tables above show the exact Monday to Sunday range of every week.