Week numbers 2027

2027 has 52 weeks. Week 1 starts on Monday, January 4, 2027 and week 52 ends on Sunday, January 2, 2028.

All week numbers of 2027, with the start and end date of every week, in both the ISO-8601 standard and the US system.

All weeks of 2027

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Week numbers 2027 (ISO-8601)
WeekStart dateEnd date
53Friday, January 1, 2027Sunday, January 3, 2027
1Monday, January 4, 2027Sunday, January 10, 2027
2Monday, January 11, 2027Sunday, January 17, 2027
3Monday, January 18, 2027Sunday, January 24, 2027
4Monday, January 25, 2027Sunday, January 31, 2027
5Monday, February 1, 2027Sunday, February 7, 2027
6Monday, February 8, 2027Sunday, February 14, 2027
7Monday, February 15, 2027Sunday, February 21, 2027
8Monday, February 22, 2027Sunday, February 28, 2027
9Monday, March 1, 2027Sunday, March 7, 2027
10Monday, March 8, 2027Sunday, March 14, 2027
11Monday, March 15, 2027Sunday, March 21, 2027
12Monday, March 22, 2027Sunday, March 28, 2027
13Monday, March 29, 2027Sunday, April 4, 2027
14Monday, April 5, 2027Sunday, April 11, 2027
15Monday, April 12, 2027Sunday, April 18, 2027
16Monday, April 19, 2027Sunday, April 25, 2027
17Monday, April 26, 2027Sunday, May 2, 2027
18Monday, May 3, 2027Sunday, May 9, 2027
19Monday, May 10, 2027Sunday, May 16, 2027
20Monday, May 17, 2027Sunday, May 23, 2027
21Monday, May 24, 2027Sunday, May 30, 2027
22Monday, May 31, 2027Sunday, June 6, 2027
23Monday, June 7, 2027Sunday, June 13, 2027
24Monday, June 14, 2027Sunday, June 20, 2027
25Monday, June 21, 2027Sunday, June 27, 2027
26Monday, June 28, 2027Sunday, July 4, 2027
27Monday, July 5, 2027Sunday, July 11, 2027
28Monday, July 12, 2027Sunday, July 18, 2027
29Monday, July 19, 2027Sunday, July 25, 2027
30Monday, July 26, 2027Sunday, August 1, 2027
31Monday, August 2, 2027Sunday, August 8, 2027
32Monday, August 9, 2027Sunday, August 15, 2027
33Monday, August 16, 2027Sunday, August 22, 2027
34Monday, August 23, 2027Sunday, August 29, 2027
35Monday, August 30, 2027Sunday, September 5, 2027
36Monday, September 6, 2027Sunday, September 12, 2027
37Monday, September 13, 2027Sunday, September 19, 2027
38Monday, September 20, 2027Sunday, September 26, 2027
39Monday, September 27, 2027Sunday, October 3, 2027
40Monday, October 4, 2027Sunday, October 10, 2027
41Monday, October 11, 2027Sunday, October 17, 2027
42Monday, October 18, 2027Sunday, October 24, 2027
43Monday, October 25, 2027Sunday, October 31, 2027
44Monday, November 1, 2027Sunday, November 7, 2027
45Monday, November 8, 2027Sunday, November 14, 2027
46Monday, November 15, 2027Sunday, November 21, 2027
47Monday, November 22, 2027Sunday, November 28, 2027
48Monday, November 29, 2027Sunday, December 5, 2027
49Monday, December 6, 2027Sunday, December 12, 2027
50Monday, December 13, 2027Sunday, December 19, 2027
51Monday, December 20, 2027Sunday, December 26, 2027
52Monday, December 27, 2027Friday, December 31, 2027

The first and last row of a year overview can be shorter than seven days.

Week numbers according to the international standard. Source: ISO 8601. More about our sources

The US count (weeks start on Sunday, week 1 contains 1 January) is a common convention without an official standard.

US week numbers 2027

In the United States weeks start on Sunday and week 1 is the week containing January 1 (as in Excel WEEKNUM and Outlook).

US week numbers 2027 (Sunday to Saturday)
WeekStart dateEnd date
1Friday, January 1, 2027Saturday, January 2, 2027
2Sunday, January 3, 2027Saturday, January 9, 2027
3Sunday, January 10, 2027Saturday, January 16, 2027
4Sunday, January 17, 2027Saturday, January 23, 2027
5Sunday, January 24, 2027Saturday, January 30, 2027
6Sunday, January 31, 2027Saturday, February 6, 2027
7Sunday, February 7, 2027Saturday, February 13, 2027
8Sunday, February 14, 2027Saturday, February 20, 2027
9Sunday, February 21, 2027Saturday, February 27, 2027
10Sunday, February 28, 2027Saturday, March 6, 2027
11Sunday, March 7, 2027Saturday, March 13, 2027
12Sunday, March 14, 2027Saturday, March 20, 2027
13Sunday, March 21, 2027Saturday, March 27, 2027
14Sunday, March 28, 2027Saturday, April 3, 2027
15Sunday, April 4, 2027Saturday, April 10, 2027
16Sunday, April 11, 2027Saturday, April 17, 2027
17Sunday, April 18, 2027Saturday, April 24, 2027
18Sunday, April 25, 2027Saturday, May 1, 2027
19Sunday, May 2, 2027Saturday, May 8, 2027
20Sunday, May 9, 2027Saturday, May 15, 2027
21Sunday, May 16, 2027Saturday, May 22, 2027
22Sunday, May 23, 2027Saturday, May 29, 2027
23Sunday, May 30, 2027Saturday, June 5, 2027
24Sunday, June 6, 2027Saturday, June 12, 2027
25Sunday, June 13, 2027Saturday, June 19, 2027
26Sunday, June 20, 2027Saturday, June 26, 2027
27Sunday, June 27, 2027Saturday, July 3, 2027
28Sunday, July 4, 2027Saturday, July 10, 2027
29Sunday, July 11, 2027Saturday, July 17, 2027
30Sunday, July 18, 2027Saturday, July 24, 2027
31Sunday, July 25, 2027Saturday, July 31, 2027
32Sunday, August 1, 2027Saturday, August 7, 2027
33Sunday, August 8, 2027Saturday, August 14, 2027
34Sunday, August 15, 2027Saturday, August 21, 2027
35Sunday, August 22, 2027Saturday, August 28, 2027
36Sunday, August 29, 2027Saturday, September 4, 2027
37Sunday, September 5, 2027Saturday, September 11, 2027
38Sunday, September 12, 2027Saturday, September 18, 2027
39Sunday, September 19, 2027Saturday, September 25, 2027
40Sunday, September 26, 2027Saturday, October 2, 2027
41Sunday, October 3, 2027Saturday, October 9, 2027
42Sunday, October 10, 2027Saturday, October 16, 2027
43Sunday, October 17, 2027Saturday, October 23, 2027
44Sunday, October 24, 2027Saturday, October 30, 2027
45Sunday, October 31, 2027Saturday, November 6, 2027
46Sunday, November 7, 2027Saturday, November 13, 2027
47Sunday, November 14, 2027Saturday, November 20, 2027
48Sunday, November 21, 2027Saturday, November 27, 2027
49Sunday, November 28, 2027Saturday, December 4, 2027
50Sunday, December 5, 2027Saturday, December 11, 2027
51Sunday, December 12, 2027Saturday, December 18, 2027
52Sunday, December 19, 2027Saturday, December 25, 2027
53Sunday, December 26, 2027Friday, December 31, 2027

How do week numbers work?

Most of the world uses the ISO-8601 standard: weeks start on Monday and week 1 is the week with the first Thursday of the year. A year can therefore start in week 52 or 53 of the previous year.

Week numbers in 2027: US and ISO

In the US system, 2027 is divided into 53 numbered weeks. Week 1 starts on January 1, a Friday, and ends on the first Saturday of the year. Every following week runs from Sunday to Saturday, and the last week ends on December 31, so the first and last weeks can be shorter than seven days.

Under ISO 8601, 2027 has 52 weeks, each running from Monday to Sunday. ISO week 1 starts on Monday, January 4, 2027.

The next year with 53 ISO weeks is 2032.

Up to and including January 3, the first days of January still belong to ISO week 53 of 2026, while in the US system they are already week 1.

Using the 2027 week numbers

The tables above show the start and end date of every week in both systems. That makes it easy to find the dates for a week number, for a delivery, a payroll period or a project deadline, whichever system your company or partner uses.

You can print all week numbers of 2027 or download them as an Excel or PDF file.

Frequently asked questions

How many weeks are there in 2027?

2027 has 52 weeks under ISO-8601 and 53 weeks in the US system, where a new week starts every Sunday.

When does week 1 of 2027 start?

In the US system, week 1 starts on January 1. Under ISO-8601, week 1 of 2027 starts on Monday, January 4, 2027.

Can I download the 2027 week numbers?

Yes, use the buttons next to the table: print, Excel or PDF.

What day of the week does 2027 start on?

January 1, 2027 is a Friday. In the US system, week 1 runs from that day until the first Saturday of the year.

How many weeks are there in 2028?

Under ISO-8601, 2028 has 52 weeks.

See also

In other countries