Week Numbers

Week Numbers for the Year 2027

Knowing the week numbers for 2027 can be helpful for planning events, managing projects, or simply staying organized. Here’s a complete breakdown of all the weeks in 2027, including their start and end dates.

What Are Week Numbers?

Week numbers are a standardized way of counting the weeks in a year. Each week is assigned a number from 1 to 52 (sometimes 53), depending on how the calendar aligns with the start of the year. According to the ISO 8601 standard, each week starts on a Monday, and Week 1 is the week that contains the first Thursday of the year.

Week Number Table for 2027

Week NumberStart DateEnd Date
Week 1Jan 4, 2027Jan 10, 2027
Week 2Jan 11, 2027Jan 17, 2027
Week 3Jan 18, 2027Jan 24, 2027
Week 4Jan 25, 2027Jan 31, 2027
Week 5Feb 1, 2027Feb 7, 2027
Week 6Feb 8, 2027Feb 14, 2027
Week 7Feb 15, 2027Feb 21, 2027
Week 8Feb 22, 2027Feb 28, 2027
Week 9Mar 1, 2027Mar 7, 2027
Week 10Mar 8, 2027Mar 14, 2027
Week 11Mar 15, 2027Mar 21, 2027
Week 12Mar 22, 2027Mar 28, 2027
Week 13Mar 29, 2027Apr 4, 2027
Week 14Apr 5, 2027Apr 11, 2027
Week 15Apr 12, 2027Apr 18, 2027
Week 16Apr 19, 2027Apr 25, 2027
Week 17Apr 26, 2027May 2, 2027
Week 18May 3, 2027May 9, 2027
Week 19May 10, 2027May 16, 2027
Week 20May 17, 2027May 23, 2027
Week 21May 24, 2027May 30, 2027
Week 22May 31, 2027Jun 6, 2027
Week 23Jun 7, 2027Jun 13, 2027
Week 24Jun 14, 2027Jun 20, 2027
Week 25Jun 21, 2027Jun 27, 2027
Week 26Jun 28, 2027Jul 4, 2027
Week 27Jul 5, 2027Jul 11, 2027
Week 28Jul 12, 2027Jul 18, 2027
Week 29Jul 19, 2027Jul 25, 2027
Week 30Jul 26, 2027Aug 1, 2027
Week 31Aug 2, 2027Aug 8, 2027
Week 32Aug 9, 2027Aug 15, 2027
Week 33Aug 16, 2027Aug 22, 2027
Week 34Aug 23, 2027Aug 29, 2027
Week 35Aug 30, 2027Sep 5, 2027
Week 36Sep 6, 2027Sep 12, 2027
Week 37Sep 13, 2027Sep 19, 2027
Week 38Sep 20, 2027Sep 26, 2027
Week 39Sep 27, 2027Oct 3, 2027
Week 40Oct 4, 2027Oct 10, 2027
Week 41Oct 11, 2027Oct 17, 2027
Week 42Oct 18, 2027Oct 24, 2027
Week 43Oct 25, 2027Oct 31, 2027
Week 44Nov 1, 2027Nov 7, 2027
Week 45Nov 8, 2027Nov 14, 2027
Week 46Nov 15, 2027Nov 21, 2027
Week 47Nov 22, 2027Nov 28, 2027
Week 48Nov 29, 2027Dec 5, 2027
Week 49Dec 6, 2027Dec 12, 2027
Week 50Dec 13, 2027Dec 19, 2027
Week 51Dec 20, 2027Dec 26, 2027
Week 52Dec 27, 2027Jan 2, 2028
Week 53Jan 3, 2028Jan 9, 2028

Yes, 2027 has 53 weeks! This happens when the year starts on a Thursday or is a leap year that ends on a Thursday—allowing for that extra ISO week.

Why Are Week Numbers Useful?

Week numbers are used in a variety of scenarios across professional and personal settings:

Fun Fact

The ISO 8601 week-numbering system was first introduced in 1988 and is used by many countries around the world, especially in Europe. The U.S. doesn't commonly use it, but many global systems rely on it for consistency.

Find the Week Number of Any Date

Want to know the week number of a specific date? In PHP, you can use the DateTime object like this:

Week number is: 14

List the week numbers of the coming years.