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Week Numbers for 2021

Complete list of ISO 8601 week number for 2021, showing the start and end dates for each week. Week 1 contains January 4th.

52 weeks in 2021

←2020
2021
2022→
Week 01
From Date (Monday): January 4, 2021
To Date (Sunday): January 10, 2021
Week 02
From Date (Monday): January 11, 2021
To Date (Sunday): January 17, 2021
Week 03
From Date (Monday): January 18, 2021
To Date (Sunday): January 24, 2021
Week 04
From Date (Monday): January 25, 2021
To Date (Sunday): January 31, 2021
Week 05
From Date (Monday): February 1, 2021
To Date (Sunday): February 7, 2021
Week 06
From Date (Monday): February 8, 2021
To Date (Sunday): February 14, 2021
Week 07
From Date (Monday): February 15, 2021
To Date (Sunday): February 21, 2021
Week 08
From Date (Monday): February 22, 2021
To Date (Sunday): February 28, 2021
Week 09
From Date (Monday): March 1, 2021
To Date (Sunday): March 7, 2021
Week 10
From Date (Monday): March 8, 2021
To Date (Sunday): March 14, 2021
Week 11
From Date (Monday): March 15, 2021
To Date (Sunday): March 21, 2021
Week 12
From Date (Monday): March 22, 2021
To Date (Sunday): March 28, 2021
Week 13
From Date (Monday): March 29, 2021
To Date (Sunday): April 4, 2021
Week 14
From Date (Monday): April 5, 2021
To Date (Sunday): April 11, 2021
Week 15
From Date (Monday): April 12, 2021
To Date (Sunday): April 18, 2021
Week 16
From Date (Monday): April 19, 2021
To Date (Sunday): April 25, 2021
Week 17
From Date (Monday): April 26, 2021
To Date (Sunday): May 2, 2021
Week 18
From Date (Monday): May 3, 2021
To Date (Sunday): May 9, 2021
Week 19
From Date (Monday): May 10, 2021
To Date (Sunday): May 16, 2021
Week 20
From Date (Monday): May 17, 2021
To Date (Sunday): May 23, 2021
Week 21
From Date (Monday): May 24, 2021
To Date (Sunday): May 30, 2021
Week 22
From Date (Monday): May 31, 2021
To Date (Sunday): June 6, 2021
Week 23
From Date (Monday): June 7, 2021
To Date (Sunday): June 13, 2021
Week 24
From Date (Monday): June 14, 2021
To Date (Sunday): June 20, 2021
Week 25
From Date (Monday): June 21, 2021
To Date (Sunday): June 27, 2021
Week 26
From Date (Monday): June 28, 2021
To Date (Sunday): July 4, 2021
Week 27
From Date (Monday): July 5, 2021
To Date (Sunday): July 11, 2021
Week 28
From Date (Monday): July 12, 2021
To Date (Sunday): July 18, 2021
Week 29
From Date (Monday): July 19, 2021
To Date (Sunday): July 25, 2021
Week 30
From Date (Monday): July 26, 2021
To Date (Sunday): August 1, 2021
Week 31
From Date (Monday): August 2, 2021
To Date (Sunday): August 8, 2021
Week 32
From Date (Monday): August 9, 2021
To Date (Sunday): August 15, 2021
Week 33
From Date (Monday): August 16, 2021
To Date (Sunday): August 22, 2021
Week 34
From Date (Monday): August 23, 2021
To Date (Sunday): August 29, 2021
Week 35
From Date (Monday): August 30, 2021
To Date (Sunday): September 5, 2021
Week 36
From Date (Monday): September 6, 2021
To Date (Sunday): September 12, 2021
Week 37
From Date (Monday): September 13, 2021
To Date (Sunday): September 19, 2021
Week 38
From Date (Monday): September 20, 2021
To Date (Sunday): September 26, 2021
Week 39
From Date (Monday): September 27, 2021
To Date (Sunday): October 3, 2021
Week 40
From Date (Monday): October 4, 2021
To Date (Sunday): October 10, 2021
Week 41
From Date (Monday): October 11, 2021
To Date (Sunday): October 17, 2021
Week 42
From Date (Monday): October 18, 2021
To Date (Sunday): October 24, 2021
Week 43
From Date (Monday): October 25, 2021
To Date (Sunday): October 31, 2021
Week 44
From Date (Monday): November 1, 2021
To Date (Sunday): November 7, 2021
Week 45
From Date (Monday): November 8, 2021
To Date (Sunday): November 14, 2021
Week 46
From Date (Monday): November 15, 2021
To Date (Sunday): November 21, 2021
Week 47
From Date (Monday): November 22, 2021
To Date (Sunday): November 28, 2021
Week 48
From Date (Monday): November 29, 2021
To Date (Sunday): December 5, 2021
Week 49
From Date (Monday): December 6, 2021
To Date (Sunday): December 12, 2021
Week 50
From Date (Monday): December 13, 2021
To Date (Sunday): December 19, 2021
Week 51
From Date (Monday): December 20, 2021
To Date (Sunday): December 26, 2021
Week 52
From Date (Monday): December 27, 2021
To Date (Sunday): January 2, 2022

This 2021 ISO week calendar maps out when each week begins (Monday) and wraps up (Sunday) — so you can keep sprints, payroll cycles, and team reporting on track without guesswork.

  • •Weeks are grouped by quarter, making it easier to align product launches with your fiscal calendar.
  • •The current week automatically highlights based on your timezone — perfect when your team spans multiple cities.
  • •Download the calendar images to drop into your briefs, dashboards, or planning docs.

Need a different year? The year selector lets you jump anywhere from 2015 to 2035 in one click.

2021 Week Numbers Calendar Images

2021 Week Number Calendar - Blue Purple Theme

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2021 Week Number Calendar - Light Theme

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Select Year for Week Number

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Week Numbers 2021 - Complete with Start and End Dates