WEEKNUM

Contents

# Hàm WEEKNUM

WEEKNUM calculates the week number of the year for the internal date value as defined in ODF OpenFormula and compatible with other spreadsheet applications.

Supported are two week numbering systems:

Hệ thống | Mô tả
--- | ---
System 1 | The week containing January 1 is the first week of the year, and is numbered week 1.
System 2 | The week containing the first Thursday of the year is the first week of the year, and is numbered week 1. That means that week number 1 of any year is the week that contains January 4th. ISO 8601 defines this system and that the week starts on Monday.

This function is part of the Open Document Format for Office Applications (OpenDocument) standard Version 1.2. (ISO/IEC 26300:2-2015)

### Cú pháp

WEEKNUM(Số; Chế_độ)

Số là số của ngày tháng nội bộ.

Mode sets the start of the week and the week numbering system. This parameter is optional, if omitted the default value is 1.

Hệ thống | Chế độ | Day of the week
--- | --- | ---
System 1 | 1 | Sunday
2 | Thứ Hai
11 | Thứ Hai
12 | Thứ Ba
13 | Thứ Tư
14 | Thứ Năm
15 | Thứ Sáu
16 | Thứ Bảy
17 | Sunday
System 2 | 21 | Monday (ISO 8601)
150 | (ISO 8601, for interoperability with Gnumeric)

When entering dates as part of formulas, slashes or dashes used as date separators are interpreted as arithmetic operators. Therefore, dates entered in this format are not recognized as dates and result in erroneous calculations. To keep dates from being interpreted as parts of formulas use the DATE function, for example, DATE(1954;7;20), or place the date in quotation marks and use the ISO 8601 notation, for example, "1954-07-20". Avoid using locale dependent date formats such as "07/20/54", the calculation may produce errors if the document is loaded under different locale settings.

Unambiguous conversion is possible for ISO 8601 dates and times in their extended formats with separators. If a #VALUE! error occurs, then unselect Generate #VALUE! error in LibreOffice - PreferencesTools - Options - LibreOffice Calc - Formula, button Details... in section "Detailed Calculation Settings", Conversion from text to number list box.

### Ví dụ

=WEEKNUM(DATE(1995;1;1);1) returns 1

=WEEKNUM(DATE(1995;1;1);2) returns 1. Using System 1, the week containing January 1 is the first week of the year.

=WEEKNUM(DATE(1995;1;1);21) returns 52. Week 1 starts on Monday, 1995-01-02.

=WEEKNUM(DATE(1999;1;1);21) returns 53. Week 1 starts on Monday, 1999-01-04.

Chủ đề Liên quan

WEEKNUM wiki page.

Date & Time Functions

Hàm DATE

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Hàm DATEVALUE

Hàm DAY

Hàm DAYS

Hàm DAYS360

DAYSINMONTH

DAYSINYEAR

Hàm EASTERSUNDAY

Hàm EDATE

Hàm EOMONTH

Hàm HOUR

ISLEAPYEAR

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Hàm MINUTE

Hàm MONTH

MONTHS

NETWORKDAYS

NETWORKDAYS.INTL

Hàm NOW

Hàm SECOND

Hàm TIME

Hàm TIMEVALUE

Hàm TODAY

WEEKDAY

Hàm WEEKNUM

Hàm WEEKNUM_ADD

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WEEKS

WEEKSINYEAR

Hàm WORKDAY

WORKDAY.INTL

Hàm YEAR

Hàm YEARFRAC

YEARS