Summary
The Excel WEEKDAY function returns a number representing the day of the week for a given date. The function can be configured to determine which day is considered the first day of the week, with Sunday as the default first day.
Syntax
=WEEKDAY(serial_number, [return_type])
- serial_number: The date for which the day of the week is required.
- return_type: [Optional] A number representing the day of week mapping scheme. Default is 1.
Return value
A number between 1 and 7, representing the day of the week.
How to use
The WEEKDAY function is used to determine the day of the week for a given date. It accepts a date (serial_number) and an optional return_type, which specifies the numbering scheme for the days of the week.
Return Types and Their Day Mapping:
1 (Default):1 (Sunday) to 7 (Saturday)2: 1 (Monday) to 7 (Sunday)3: 0 (Monday) to 6 (Sunday)11: 1 (Monday) to 7 (Sunday)12: 1 (Tuesday) to 7 (Monday)13: 1 (Wednesday) to 7 (Tuesday)14: 1 (Thursday) to 7 (Wednesday)15: 1 (Friday) to 7 (Thursday)16: 1 (Saturday) to 7 (Friday)17: 1 (Sunday) to 7 (Saturday)
Examples
Simple WEEKDAY
Identifying the Day of the Week:
=WEEKDAY("2021-01-01")
Returns 6, indicating that January 1, 2021, was a Friday.
WEEKDAY with Return Type
Customizing First Day of the Week:
=WEEKDAY("2021-01-01", 2)
Using return type 2, this formula returns 5, mapping January 1, 2021, to a Friday, with Monday as the first day of the week.
WEEKDAY and TODAY
Planning Based on Day of the Week:
=WEEKDAY(TODAY(), 3)
Calculates the day of the week for the current date, with Monday as 0 and Sunday as 6.
Additional Notes
- The WEEKDAY function can return a value even if the date is blank, which may require handling in some applications.
- Useful for scheduling, planning, and other scenarios where the day of the week plays a crucial role.
- The return value of WEEKDAY is highly customizable, allowing for various weekly scheduling standards.