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2013 Week Numbers

ISO 8601 week numbers — every week runs Monday to Sunday.

Current ISO week number

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Week Numbers 2013

Week #	Start date (Mon)	End date (Sun)
▸ 1	Mon, 31 Dec 2012	Sun, 6 Jan 2013
▸ 2	Mon, 7 Jan 2013	Sun, 13 Jan 2013
▸ 3	Mon, 14 Jan 2013	Sun, 20 Jan 2013
▸ 4	Mon, 21 Jan 2013	Sun, 27 Jan 2013
▸ 5	Mon, 28 Jan 2013	Sun, 3 Feb 2013
▸ 6	Mon, 4 Feb 2013	Sun, 10 Feb 2013
▸ 7	Mon, 11 Feb 2013	Sun, 17 Feb 2013
▸ 8	Mon, 18 Feb 2013	Sun, 24 Feb 2013
▸ 9	Mon, 25 Feb 2013	Sun, 3 Mar 2013
▸ 10	Mon, 4 Mar 2013	Sun, 10 Mar 2013
▸ 11	Mon, 11 Mar 2013	Sun, 17 Mar 2013
▸ 12	Mon, 18 Mar 2013	Sun, 24 Mar 2013
▸ 13	Mon, 25 Mar 2013	Sun, 31 Mar 2013
▸ 14	Mon, 1 Apr 2013	Sun, 7 Apr 2013
▸ 15	Mon, 8 Apr 2013	Sun, 14 Apr 2013
▸ 16	Mon, 15 Apr 2013	Sun, 21 Apr 2013
▸ 17	Mon, 22 Apr 2013	Sun, 28 Apr 2013
▸ 18	Mon, 29 Apr 2013	Sun, 5 May 2013
▸ 19	Mon, 6 May 2013	Sun, 12 May 2013
▸ 20	Mon, 13 May 2013	Sun, 19 May 2013
▸ 21	Mon, 20 May 2013	Sun, 26 May 2013
▸ 22	Mon, 27 May 2013	Sun, 2 Jun 2013
▸ 23	Mon, 3 Jun 2013	Sun, 9 Jun 2013
▸ 24	Mon, 10 Jun 2013	Sun, 16 Jun 2013
▸ 25	Mon, 17 Jun 2013	Sun, 23 Jun 2013
▸ 26	Mon, 24 Jun 2013	Sun, 30 Jun 2013
▸ 27	Mon, 1 Jul 2013	Sun, 7 Jul 2013
▸ 28	Mon, 8 Jul 2013	Sun, 14 Jul 2013
▸ 29	Mon, 15 Jul 2013	Sun, 21 Jul 2013
▸ 30	Mon, 22 Jul 2013	Sun, 28 Jul 2013
▸ 31	Mon, 29 Jul 2013	Sun, 4 Aug 2013
▸ 32	Mon, 5 Aug 2013	Sun, 11 Aug 2013
▸ 33	Mon, 12 Aug 2013	Sun, 18 Aug 2013
▸ 34	Mon, 19 Aug 2013	Sun, 25 Aug 2013
▸ 35	Mon, 26 Aug 2013	Sun, 1 Sep 2013
▸ 36	Mon, 2 Sep 2013	Sun, 8 Sep 2013
▸ 37	Mon, 9 Sep 2013	Sun, 15 Sep 2013
▸ 38	Mon, 16 Sep 2013	Sun, 22 Sep 2013
▸ 39	Mon, 23 Sep 2013	Sun, 29 Sep 2013
▸ 40	Mon, 30 Sep 2013	Sun, 6 Oct 2013
▸ 41	Mon, 7 Oct 2013	Sun, 13 Oct 2013
▸ 42	Mon, 14 Oct 2013	Sun, 20 Oct 2013
▸ 43	Mon, 21 Oct 2013	Sun, 27 Oct 2013
▸ 44	Mon, 28 Oct 2013	Sun, 3 Nov 2013
▸ 45	Mon, 4 Nov 2013	Sun, 10 Nov 2013
▸ 46	Mon, 11 Nov 2013	Sun, 17 Nov 2013
▸ 47	Mon, 18 Nov 2013	Sun, 24 Nov 2013
▸ 48	Mon, 25 Nov 2013	Sun, 1 Dec 2013
▸ 49	Mon, 2 Dec 2013	Sun, 8 Dec 2013
▸ 50	Mon, 9 Dec 2013	Sun, 15 Dec 2013
▸ 51	Mon, 16 Dec 2013	Sun, 22 Dec 2013
▸ 52	Mon, 23 Dec 2013	Sun, 29 Dec 2013

About ISO 8601 Week Numbers

Under the ISO 8601 standard, weeks start on Monday and are numbered from 1 to 52 or 53. Week 1 is the week that contains the first Thursday of the year — equivalently, the week containing January 4th. As a result, the first few days of January can fall in the last week of the previous year, and the last days of December can fall in week 1 of the next year.

A year has 53 ISO weeks when it starts on a Thursday, or on a Wednesday in a leap year; otherwise it has 52. 2013 has 52 ISO weeks.