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WEEKNUM

Definition of WEEKNUM

Returns a number representing the week of the year where the provided date falls.

Sample Usage

WEEKNUM(DATE(1969, 7, 20), 1)

WEEKNUM("12/09/1948", 2)

WEEKNUM("6/14/2002")

Syntax

WEEKNUM(date, [type])
  • date - The date for which to determine the week number. Must be a reference to a cell containing a date, a function returning a date type, or a number.
  • type - [ OPTIONAL - default is 1 ] - A number representing the day that a week starts on as well as the system used for determining the first week of the year (1=Sunday, 2=Monday).

Notes

  • When inputting the date, it is best to use the DATE function, as text values may return errors.
  • Behind the scenes, there are two week numbering "systems" used for this function:
    • System 1 - The first week of the year is considered to be the week containing January 1, which is numbered week 1.
    • System 2 - The first week of the year is considered to be the week containing the first Thursday of the year, which is numbered as week 1. System 2 is the approach specified in ISO 8601, also known as the European system for numbering weeks.
  • For each type, the start day and end day of a week are defined as follows when counting week numbers:
     

    typeDay week begins onDay week ends onSystem
    1 or omittedSundaySaturday1
    2MondaySunday1
    11MondaySunday1
    12TuesdayMonday1
    13WednesdayTuesday1
    14ThursdayWednesday1
    15FridayThursday1
    16SaturdayFriday1
    17SundaySaturday1
    21MondaySunday2

See Also

WEEKDAY: Returns a number representing the day of the week of the date provided.

DAYS360: Returns the difference between two days based on the 360 day year used in some financial interest calculations.

DATE: Converts a provided year, month, and day into a date.

DATEVALUE: Converts a provided date string in a known format to a date value.

In order to use the WEEKNUM formula, start with your edited Excellentable

Then type in the WEEKNUM Formula in the area you would like to display the outcome:

By adding the values you would like to calculate, Excellentable generates the outcome:

A
B
C
1
State
Population
Total area in mi2
Land area in mi2
Water area in mi2
2
Alabama
4833722
52,420 (135,767)
3
Alaska
735132
665,384 (1,723,337)
4
Arizona
6626624
113,990 (295,233)
5
Arkansas
2959373
53,179 (137,733)
6
California
38332521
163,695 (423,968)
7
Colorado
5268367
104,094 (269,602)
8
Connecticut
3596080
5,543 (14,356)
9
Delaware
925749
2,489 (6,446)
10
Florida
19552860
65,758 (170,312)
11
Georgia
9992167
59,425 (153,910)
12
Hawaii
1404054
10,932 (28,314)
13
Idaho
1612136
83,569 (216,443)
14
D
E
F
1
House seat(s)
Date
2
50,645 (131,170)
1,775 (4,597)
7
3
570,641 (1,477,950)
94,743 (245,383)
1
4
113,594 (294,207)
396 (1,026)
9
5
52,035 (134,770)
1,143 (2,960)
4
6
155,779 (403,466)
7,916 (20,502)
53
7
103,642 (268,432)
452 (1,171)
7
8
4,842 (12,541)
701 (1,816)
5
9
1,949 (5,048)
540 (1,399)
1
10
53,625 (138,888)
12,133 (31,424)
27
11
57,513 (148,958)
1,912 (4,950)
14
12
6,423 (16,635)
4,509 (11,678)
2
13
82,643 (214,044)
926 (2,398)
2
14
WEEKNUM
G
1
2
7/5/2008
3
7/6/2008
4
7/7/2008
5
7/8/2016
6
7/9/2008
7
7/10/2015
8
7/10/2015
9
7/12/2014
10
7/5/2008
11
7/5/2008
12
7/5/2008
13
7/5/2008
14
28

 

 

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