目次

# WEEKDAY

Returns the day of the week for the given date value. The day is returned as an integer between 1 (Sunday) and 7 (Saturday) if no type or type=1 is specified. For other types, see the table below.

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

### 構文

WEEKDAY(Number [; Type])

数値 に入力したシリアル値に対応する曜日が返されます。

Type is optional and determines the type of calculation.

Type | Weekday number returned
--- | ---
1 or omitted | 1 (Sunday) through 7 (Saturday). For compatibility with Microsoft Excel.
2 | 1 (Monday) through 7 (Sunday).
3 | 0 (Monday) through 6 (Sunday)
11 | 1 (Monday) through 7 (Sunday).
12 | 1 (Tuesday) through 7 (Monday).
13 | 1 (Wednesday) through 7 (Tuesday).
14 | 1 (Thursday) through 7 (Wednesday).
15 | 1 (Friday) through 7 (Thursday).
16 | 1 (Saturday) through 7 (Friday).
17 | 1 (Sunday) through 7 (Saturday).

These values apply only to the standard date format that you select under LibreOffice - Preferences Tools - Options- LibreOffice Calc - Calculate.

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 - Preferences Tools - Options - LibreOffice Calc - Formula, button Details... in section "Detailed Calculation Settings", Conversion from text to number list box.

### 例

=WEEKDAY("2000-06-14") returns 4 (the Type parameter is missing, therefore the standard count is used. The standard count starts with Sunday as day number 1. June 14, 2000 was a Wednesday and therefore day number 4).

=WEEKDAY("1996-07-24";2) returns 3 (the Type parameter is 2, therefore Monday is day number 1. July 24, 1996 was a Wednesday and therefore day number 3).

=WEEKDAY("1996-07-24";1) returns 4 (the Type parameter is 1, therefore Sunday is day number 1. July 24, 1996 was a Wednesday and therefore day number 4).

=WEEKDAY("2017-05-02";14) returns 6 (the Type parameter is 14, therefore Thursday is day number 1. May 2, 2017 was a Tuesday and therefore day number 6)

=WEEKDAY(NOW()) returns the number of the current day.

To obtain a function indicating whether a day in A1 is a business day, use the IF and WEEKDAY functions as follows:
IF(WEEKDAY(A1;2)<6;"Business day";"Weekend")

関連項目

WEEKDAY wiki page.

日付と時刻 関数

DATE

DATEDIF

DATEVALUE

DAY

DAYS

DAYS360

DAYSINMONTH

DAYSINYEAR

EASTERSUNDAY

EDATE

EOMONTH

HOUR

ISLEAPYEAR

ISOWEEKNUM

MINUTE

MONTH

MONTHS

NETWORKDAYS

NETWORKDAYS.INTL

NOW

SECOND

TIME

TIMEVALUE

TODAY

WEEKDAY

WEEKNUM

WEEKNUM_ADD

WEEKNUM_OOO

WEEKS

WEEKSINYEAR

WORKDAY

WORKDAY.INTL

YEAR

YEARFRAC

YEARS