Week numbers 1851

1851 has 52 ISO weeks. Week 1 of 1851 starts on December 30, 1850 and ends on January 5, 1851 (ISO 8601, Monday to Sunday).

1851 at a glance

Weeks in 185152
Week 1December 30, 1850 – January 5, 1851
Week 52December 22, 1851 – December 28, 1851
Days in 1851365
Leap yearNo

All Weeks in 1851

Week From To Month
Week 1 in 1851 December 30, 1850 January 5, 1851 December / January
Week 2 in 1851 January 6, 1851 January 12, 1851 January
Week 3 in 1851 January 13, 1851 January 19, 1851 January
Week 4 in 1851 January 20, 1851 January 26, 1851 January
Week 5 in 1851 January 27, 1851 February 2, 1851 January / February
Week 6 in 1851 February 3, 1851 February 9, 1851 February
Week 7 in 1851 February 10, 1851 February 16, 1851 February
Week 8 in 1851 February 17, 1851 February 23, 1851 February
Week 9 in 1851 February 24, 1851 March 2, 1851 February / March
Week 10 in 1851 March 3, 1851 March 9, 1851 March
Week 11 in 1851 March 10, 1851 March 16, 1851 March
Week 12 in 1851 March 17, 1851 March 23, 1851 March
Week 13 in 1851 March 24, 1851 March 30, 1851 March
Week 14 in 1851 March 31, 1851 April 6, 1851 March / April
Week 15 in 1851 April 7, 1851 April 13, 1851 April
Week 16 in 1851 April 14, 1851 April 20, 1851 April
Week 17 in 1851 April 21, 1851 April 27, 1851 April
Week 18 in 1851 April 28, 1851 May 4, 1851 April / May
Week 19 in 1851 May 5, 1851 May 11, 1851 May
Week 20 in 1851 May 12, 1851 May 18, 1851 May
Week 21 in 1851 May 19, 1851 May 25, 1851 May
Week 22 in 1851 May 26, 1851 June 1, 1851 May / June
Week 23 in 1851 June 2, 1851 June 8, 1851 June
Week 24 in 1851 June 9, 1851 June 15, 1851 June
Week 25 in 1851 June 16, 1851 June 22, 1851 June
Week 26 in 1851 June 23, 1851 June 29, 1851 June
Week 27 in 1851 June 30, 1851 July 6, 1851 June / July
Week 28 in 1851 July 7, 1851 July 13, 1851 July
Week 29 in 1851 July 14, 1851 July 20, 1851 July
Week 30 in 1851 July 21, 1851 July 27, 1851 July
Week 31 in 1851 July 28, 1851 August 3, 1851 July / August
Week 32 in 1851 August 4, 1851 August 10, 1851 August
Week 33 in 1851 August 11, 1851 August 17, 1851 August
Week 34 in 1851 August 18, 1851 August 24, 1851 August
Week 35 in 1851 August 25, 1851 August 31, 1851 August
Week 36 in 1851 September 1, 1851 September 7, 1851 September
Week 37 in 1851 September 8, 1851 September 14, 1851 September
Week 38 in 1851 September 15, 1851 September 21, 1851 September
Week 39 in 1851 September 22, 1851 September 28, 1851 September
Week 40 in 1851 September 29, 1851 October 5, 1851 September / October
Week 41 in 1851 October 6, 1851 October 12, 1851 October
Week 42 in 1851 October 13, 1851 October 19, 1851 October
Week 43 in 1851 October 20, 1851 October 26, 1851 October
Week 44 in 1851 October 27, 1851 November 2, 1851 October / November
Week 45 in 1851 November 3, 1851 November 9, 1851 November
Week 46 in 1851 November 10, 1851 November 16, 1851 November
Week 47 in 1851 November 17, 1851 November 23, 1851 November
Week 48 in 1851 November 24, 1851 November 30, 1851 November
Week 49 in 1851 December 1, 1851 December 7, 1851 December
Week 50 in 1851 December 8, 1851 December 14, 1851 December
Week 51 in 1851 December 15, 1851 December 21, 1851 December
Week 52 in 1851 December 22, 1851 December 28, 1851 December

Calendars 1851

January 1851
MoTuWeThFrSaSu
Week 112345
Week 26789101112
Week 313141516171819
Week 420212223242526
Week 52728293031
February 1851
MoTuWeThFrSaSu
Week 512
Week 63456789
Week 710111213141516
Week 817181920212223
Week 92425262728
March 1851
MoTuWeThFrSaSu
Week 912
Week 103456789
Week 1110111213141516
Week 1217181920212223
Week 1324252627282930
Week 1431
April 1851
MoTuWeThFrSaSu
Week 14123456
Week 1578910111213
Week 1614151617181920
Week 1721222324252627
Week 18282930
May 1851
MoTuWeThFrSaSu
Week 181234
Week 19567891011
Week 2012131415161718
Week 2119202122232425
Week 22262728293031
June 1851
MoTuWeThFrSaSu
Week 221
Week 232345678
Week 249101112131415
Week 2516171819202122
Week 2623242526272829
Week 2730
July 1851
MoTuWeThFrSaSu
Week 27123456
Week 2878910111213
Week 2914151617181920
Week 3021222324252627
Week 3128293031
August 1851
MoTuWeThFrSaSu
Week 31123
Week 3245678910
Week 3311121314151617
Week 3418192021222324
Week 3525262728293031
September 1851
MoTuWeThFrSaSu
Week 361234567
Week 37891011121314
Week 3815161718192021
Week 3922232425262728
Week 402930
October 1851
MoTuWeThFrSaSu
Week 4012345
Week 416789101112
Week 4213141516171819
Week 4320212223242526
Week 442728293031
November 1851
MoTuWeThFrSaSu
Week 4412
Week 453456789
Week 4610111213141516
Week 4717181920212223
Week 4824252627282930
December 1851
MoTuWeThFrSaSu
Week 491234567
Week 50891011121314
Week 5115161718192021
Week 5222232425262728
Week 1293031

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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 1851 starts on December 30, 1850 and ends on January 5, 1851 (ISO 8601, Monday to Sunday). 1851 has 52 ISO weeks.

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 1851 have?

1851 has 52 ISO weeks.

When does week 1 of 1851 start?

Week 1 of 1851 starts on December 30, 1850 and ends on January 5, 1851 (ISO 8601, Monday to Sunday).

When does the last week of 1851 end?

Week 52 of 1851 starts on December 22, 1851 and ends on December 28, 1851 (ISO 8601, Monday to Sunday).

Which years have 53 weeks?

The next years with 53 ISO weeks are 1852, 1857, 1863, 1868, 1874.

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.