WEEKDAY

Returns the day of the week corresponding to serial_number. The day is given as an integer, ranging from 1 (Sunday) to 7 (Saturday).

Syntax

WEEKDAY(serial_number,return_type)

Serial_number is the date-time code used by Microsoft Excel for date and time calculations. You can give serial_number as text, such as "15-Apr-1993" or "4-15-93", instead of as a number. The text is automatically converted to a serial number. For more information about serial_number, see NOW.

Return_type is a number that determines the type of return value.

Return_type	Number returned

1 or omitted	Numbers 1 (Sunday) through 7 (Saturday). Behaves like previous versions of Microsoft Excel.
2	Numbers 1 (Monday) through 7 (Sunday).
3	Numbers 0 (Monday) through 6 (Sunday).

Remarks

Microsoft Excel for Windows and Microsoft Excel for the Macintosh use different date systems as their default. For more information, see NOW.
You can also use the TEXT function to convert a value to a specified number format when using the 1900 date system:
TEXT("4/16/90", "dddd") equals Monday

Examples

WEEKDAY("2/14/90") equals 4 (Wednesday)

If you are using the 1900 date system (the default in Microsoft Excel for Windows), then:

WEEKDAY(29747.007) equals 4 (Wednesday)

If you are using the 1904 date system (the default in Microsoft Excel for the Macintosh), then:

WEEKDAY(29747.007) equals 3 (Tuesday)