Week numbers 161

161 has 53 ISO weeks, because 1 January 161 falls on a Thursday. Week 1: Dec 29, 160 – Jan 4, 161 · Week 53: Dec 28, 161 – Jan 3, 162

161 at a glance

Weeks in 16153
Week 1December 29, 160 – January 4, 161
Week 53December 28, 161 – January 3, 162
Days in 161365
Leap yearNo

All Weeks in 161

Week From To Month
Week 1 in 161 December 29, 160 January 4, 161 December / January
Week 2 in 161 January 5, 161 January 11, 161 January
Week 3 in 161 January 12, 161 January 18, 161 January
Week 4 in 161 January 19, 161 January 25, 161 January
Week 5 in 161 January 26, 161 February 1, 161 January / February
Week 6 in 161 February 2, 161 February 8, 161 February
Week 7 in 161 February 9, 161 February 15, 161 February
Week 8 in 161 February 16, 161 February 22, 161 February
Week 9 in 161 February 23, 161 March 1, 161 February / March
Week 10 in 161 March 2, 161 March 8, 161 March
Week 11 in 161 March 9, 161 March 15, 161 March
Week 12 in 161 March 16, 161 March 22, 161 March
Week 13 in 161 March 23, 161 March 29, 161 March
Week 14 in 161 March 30, 161 April 5, 161 March / April
Week 15 in 161 April 6, 161 April 12, 161 April
Week 16 in 161 April 13, 161 April 19, 161 April
Week 17 in 161 April 20, 161 April 26, 161 April
Week 18 in 161 April 27, 161 May 3, 161 April / May
Week 19 in 161 May 4, 161 May 10, 161 May
Week 20 in 161 May 11, 161 May 17, 161 May
Week 21 in 161 May 18, 161 May 24, 161 May
Week 22 in 161 May 25, 161 May 31, 161 May
Week 23 in 161 June 1, 161 June 7, 161 June
Week 24 in 161 June 8, 161 June 14, 161 June
Week 25 in 161 June 15, 161 June 21, 161 June
Week 26 in 161 June 22, 161 June 28, 161 June
Week 27 in 161 June 29, 161 July 5, 161 June / July
Week 28 in 161 July 6, 161 July 12, 161 July
Week 29 in 161 July 13, 161 July 19, 161 July
Week 30 in 161 July 20, 161 July 26, 161 July
Week 31 in 161 July 27, 161 August 2, 161 July / August
Week 32 in 161 August 3, 161 August 9, 161 August
Week 33 in 161 August 10, 161 August 16, 161 August
Week 34 in 161 August 17, 161 August 23, 161 August
Week 35 in 161 August 24, 161 August 30, 161 August
Week 36 in 161 August 31, 161 September 6, 161 August / September
Week 37 in 161 September 7, 161 September 13, 161 September
Week 38 in 161 September 14, 161 September 20, 161 September
Week 39 in 161 September 21, 161 September 27, 161 September
Week 40 in 161 September 28, 161 October 4, 161 September / October
Week 41 in 161 October 5, 161 October 11, 161 October
Week 42 in 161 October 12, 161 October 18, 161 October
Week 43 in 161 October 19, 161 October 25, 161 October
Week 44 in 161 October 26, 161 November 1, 161 October / November
Week 45 in 161 November 2, 161 November 8, 161 November
Week 46 in 161 November 9, 161 November 15, 161 November
Week 47 in 161 November 16, 161 November 22, 161 November
Week 48 in 161 November 23, 161 November 29, 161 November
Week 49 in 161 November 30, 161 December 6, 161 November / December
Week 50 in 161 December 7, 161 December 13, 161 December
Week 51 in 161 December 14, 161 December 20, 161 December
Week 52 in 161 December 21, 161 December 27, 161 December
Week 53 in 161 December 28, 161 January 3, 162 December / January

Calendars 161

January 161
MoTuWeThFrSaSu
Week 11234
Week 2567891011
Week 312131415161718
Week 419202122232425
Week 5262728293031
February 161
MoTuWeThFrSaSu
Week 51
Week 62345678
Week 79101112131415
Week 816171819202122
Week 9232425262728
March 161
MoTuWeThFrSaSu
Week 91
Week 102345678
Week 119101112131415
Week 1216171819202122
Week 1323242526272829
Week 143031
April 161
MoTuWeThFrSaSu
Week 1412345
Week 156789101112
Week 1613141516171819
Week 1720212223242526
Week 1827282930
May 161
MoTuWeThFrSaSu
Week 18123
Week 1945678910
Week 2011121314151617
Week 2118192021222324
Week 2225262728293031
June 161
MoTuWeThFrSaSu
Week 231234567
Week 24891011121314
Week 2515161718192021
Week 2622232425262728
Week 272930
July 161
MoTuWeThFrSaSu
Week 2712345
Week 286789101112
Week 2913141516171819
Week 3020212223242526
Week 312728293031
August 161
MoTuWeThFrSaSu
Week 3112
Week 323456789
Week 3310111213141516
Week 3417181920212223
Week 3524252627282930
Week 3631
September 161
MoTuWeThFrSaSu
Week 36123456
Week 3778910111213
Week 3814151617181920
Week 3921222324252627
Week 40282930
October 161
MoTuWeThFrSaSu
Week 401234
Week 41567891011
Week 4212131415161718
Week 4319202122232425
Week 44262728293031
November 161
MoTuWeThFrSaSu
Week 441
Week 452345678
Week 469101112131415
Week 4716171819202122
Week 4823242526272829
Week 4930
December 161
MoTuWeThFrSaSu
Week 2123456
Week 5078910111213
Week 5114151617181920
Week 5221222324252627
Week 5328293031

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Find the week number of a date

How week numbers are counted

Most of the world numbers weeks according to the ISO 8601 standard. A week starts on Monday, and week 1 is the week that contains the first Thursday of the year, which is always the week that contains 4 January.

Week 1 of 161 starts on December 29, 160 and ends on January 4, 161 (ISO 8601, Monday to Sunday). 161 has 53 ISO weeks, because 1 January 161 falls on a Thursday.

Because of this rule, the first days of January can belong to the last week of the previous year, and the last days of December can belong to week 1 of the next year.

In the United States, weeks usually start on Sunday and week 1 is the week that contains 1 January, so the US week number can differ from the ISO week number.

Frequently Asked Questions (FAQ)

How many weeks does 161 have?

161 has 53 ISO weeks, because 1 January 161 falls on a Thursday.

When does week 1 of 161 start?

Week 1 of 161 starts on December 29, 160 and ends on January 4, 161 (ISO 8601, Monday to Sunday).

When does the last week of 161 end?

Week 53 of 161 starts on December 28, 161 and ends on January 3, 162 (ISO 8601, Monday to Sunday).

Which years have 53 weeks?

The next years with 53 ISO weeks are 161, 167, 172, 178, 184.

Why do the US and Europe show different week numbers?

Europe follows ISO 8601: weeks start on Monday and week 1 is the week with the first Thursday of the year. In the US, weeks usually start on Sunday and week 1 is the week that contains 1 January, so the two numbers can differ by one.