ISO week numbers
2027 week numbers
2027 has 52 ISO weeks; week 1 starts Monday, January 4, 2027.
| Week | Monday | Sunday |
|---|---|---|
| Week 1 | Mon, Jan 4 | Sun, Jan 10 |
| Week 2 | Mon, Jan 11 | Sun, Jan 17 |
| Week 3 | Mon, Jan 18 | Sun, Jan 24 |
| Week 4 | Mon, Jan 25 | Sun, Jan 31 |
| Week 5 | Mon, Feb 1 | Sun, Feb 7 |
| Week 6 | Mon, Feb 8 | Sun, Feb 14 |
| Week 7 | Mon, Feb 15 | Sun, Feb 21 |
| Week 8 | Mon, Feb 22 | Sun, Feb 28 |
| Week 9 | Mon, Mar 1 | Sun, Mar 7 |
| Week 10 | Mon, Mar 8 | Sun, Mar 14 |
| Week 11 | Mon, Mar 15 | Sun, Mar 21 |
| Week 12 | Mon, Mar 22 | Sun, Mar 28 |
| Week 13 | Mon, Mar 29 | Sun, Apr 4 |
| Week 14 | Mon, Apr 5 | Sun, Apr 11 |
| Week 15 | Mon, Apr 12 | Sun, Apr 18 |
| Week 16 | Mon, Apr 19 | Sun, Apr 25 |
| Week 17 | Mon, Apr 26 | Sun, May 2 |
| Week 18 | Mon, May 3 | Sun, May 9 |
| Week 19 | Mon, May 10 | Sun, May 16 |
| Week 20 | Mon, May 17 | Sun, May 23 |
| Week 21 | Mon, May 24 | Sun, May 30 |
| Week 22 | Mon, May 31 | Sun, Jun 6 |
| Week 23 | Mon, Jun 7 | Sun, Jun 13 |
| Week 24 | Mon, Jun 14 | Sun, Jun 20 |
| Week 25 | Mon, Jun 21 | Sun, Jun 27 |
| Week 26 | Mon, Jun 28 | Sun, Jul 4 |
| Week 27 | Mon, Jul 5 | Sun, Jul 11 |
| Week 28 | Mon, Jul 12 | Sun, Jul 18 |
| Week 29 | Mon, Jul 19 | Sun, Jul 25 |
| Week 30 | Mon, Jul 26 | Sun, Aug 1 |
| Week 31 | Mon, Aug 2 | Sun, Aug 8 |
| Week 32 | Mon, Aug 9 | Sun, Aug 15 |
| Week 33 | Mon, Aug 16 | Sun, Aug 22 |
| Week 34 | Mon, Aug 23 | Sun, Aug 29 |
| Week 35 | Mon, Aug 30 | Sun, Sep 5 |
| Week 36 | Mon, Sep 6 | Sun, Sep 12 |
| Week 37 | Mon, Sep 13 | Sun, Sep 19 |
| Week 38 | Mon, Sep 20 | Sun, Sep 26 |
| Week 39 | Mon, Sep 27 | Sun, Oct 3 |
| Week 40 | Mon, Oct 4 | Sun, Oct 10 |
| Week 41 | Mon, Oct 11 | Sun, Oct 17 |
| Week 42 | Mon, Oct 18 | Sun, Oct 24 |
| Week 43 | Mon, Oct 25 | Sun, Oct 31 |
| Week 44 | Mon, Nov 1 | Sun, Nov 7 |
| Week 45 | Mon, Nov 8 | Sun, Nov 14 |
| Week 46 | Mon, Nov 15 | Sun, Nov 21 |
| Week 47 | Mon, Nov 22 | Sun, Nov 28 |
| Week 48 | Mon, Nov 29 | Sun, Dec 5 |
| Week 49 | Mon, Dec 6 | Sun, Dec 12 |
| Week 50 | Mon, Dec 13 | Sun, Dec 19 |
| Week 51 | Mon, Dec 20 | Sun, Dec 26 |
| Week 52 | Mon, Dec 27 | Sun, Jan 2, 2028 |
More
Week numbers by year
Frequently asked questions
How many weeks are in 2027?
52 ISO weeks. A year has 53 when it starts on a Thursday, or on a Wednesday in a leap year.
When does week 1 of 2027 start?
On Monday, January 4, 2027; the last week, week 52, ends on Sunday, January 2, 2028.