Week numbers 2027
2027 has 52 weeks. Week 1 runs from Monday, January 4, 2027 to Sunday, January 10, 2027, and week 52 ends on Sunday, January 2, 2028. The dates below follow ISO 8601: weeks start on Monday, and week 1 is the week with the year's first Thursday.
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Dates of a week
Week numbers 2027
ISO 8601 weeks start on Monday, and week 1 is the week with the year's first Thursday.
| Week | Monday | Sunday |
|---|---|---|
| 1 | Jan 4 | Jan 10 |
| 2 | Jan 11 | Jan 17 |
| 3 | Jan 18 | Jan 24 |
| 4 | Jan 25 | Jan 31 |
| 5 | Feb 1 | Feb 7 |
| 6 | Feb 8 | Feb 14 |
| 7 | Feb 15 | Feb 21 |
| 8 | Feb 22 | Feb 28 |
| 9 | Mar 1 | Mar 7 |
| 10 | Mar 8 | Mar 14 |
| 11 | Mar 15 | Mar 21 |
| 12 | Mar 22 | Mar 28 |
| 13 | Mar 29 | Apr 4 |
| 14 | Apr 5 | Apr 11 |
| 15 | Apr 12 | Apr 18 |
| 16 | Apr 19 | Apr 25 |
| 17 | Apr 26 | May 2 |
| 18 | May 3 | May 9 |
| 19 | May 10 | May 16 |
| 20 | May 17 | May 23 |
| 21 | May 24 | May 30 |
| 22 | May 31 | Jun 6 |
| 23 | Jun 7 | Jun 13 |
| 24 | Jun 14 | Jun 20 |
| 25 | Jun 21 | Jun 27 |
| 26 | Jun 28 | Jul 4 |
| Week | Monday | Sunday |
|---|---|---|
| 27 | Jul 5 | Jul 11 |
| 28 | Jul 12 | Jul 18 |
| 29 | Jul 19 | Jul 25 |
| 30 | Jul 26 | Aug 1 |
| 31 | Aug 2 | Aug 8 |
| 32 | Aug 9 | Aug 15 |
| 33 | Aug 16 | Aug 22 |
| 34 | Aug 23 | Aug 29 |
| 35 | Aug 30 | Sep 5 |
| 36 | Sep 6 | Sep 12 |
| 37 | Sep 13 | Sep 19 |
| 38 | Sep 20 | Sep 26 |
| 39 | Sep 27 | Oct 3 |
| 40 | Oct 4 | Oct 10 |
| 41 | Oct 11 | Oct 17 |
| 42 | Oct 18 | Oct 24 |
| 43 | Oct 25 | Oct 31 |
| 44 | Nov 1 | Nov 7 |
| 45 | Nov 8 | Nov 14 |
| 46 | Nov 15 | Nov 21 |
| 47 | Nov 22 | Nov 28 |
| 48 | Nov 29 | Dec 5 |
| 49 | Dec 6 | Dec 12 |
| 50 | Dec 13 | Dec 19 |
| 51 | Dec 20 | Dec 26 |
| 52 | Dec 27 | Jan 2, 2028 |
Week numbers in your calendar
Each Monday gets an all day event with its week number, from last year to three years ahead. Subscribe once and it stays up to date.
For scripts and AI agents, every week of 2027 is also plain JSON: 2027.json.
Need the days or working days between two dates? Use the day counter.
Plan your team's weeks
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Questions
- How are week numbers counted?
With ISO 8601, the standard Europe and most of the world use. Weeks start on Monday, and week 1 is the week with the year's first Thursday, which is also the week with January 4. So the last days of December can be in week 1 of the next year, and the first days of January in week 52 or 53 of the year before.
- How many weeks are in 2027?
2027 has 52 ISO weeks. A year has 53 weeks when it starts on a Thursday, or on a Wednesday in a leap year. 2026 and 2032 have 53, 2027 and 2028 have 52.
- When does week 1 of 2027 start?
On Monday, January 4, 2027. It ends on Sunday, January 10, 2027.
- Why is my US colleague's week number different?
In the US, weeks usually start on Sunday and week 1 is the week of January 1, whatever day that is. Both systems often agree, but not always: in years like 2027, where January 1 is a Friday, the US week number is one higher than the ISO one for most of the year. Pick US (Sunday) at the top of this page to see the US numbers.
- How do I show week numbers in Google Calendar?
On the web, click the gear icon, then Settings > General > View options, and check Show week numbers. To see the number as an event on your phone too, subscribe to the week numbers calendar under Week numbers in your calendar on this page.
- How do I show week numbers in Outlook?
In the new Outlook and Outlook on the web, open the calendar, then View > Calendar settings > Calendar appearance, check Show week numbers and save. For ISO numbers, set Start the first week of the year on to the first four-day week. In classic Outlook, go to File > Options > Calendar and check Show week numbers in the month view and in the Date Navigator.
- How do I get the week number of a date in Excel or Google Sheets?
Use
=ISOWEEKNUM(A1)for the ISO week number of the date in A1.=WEEKNUM(A1)gives the US week number, with weeks starting on Sunday.
Reminders in Slack
TurnShift is this calendar for teams on Slack: each person gets a message before their shift, and books their own shifts from there.