Excel: EOMONTH, WEEKNUM & WEEKDAY Functions

EOMONTH

EOMONTH function in excel returns the last day of the month or months in the past or future. You can use EDATE to calculate expiration dates, due dates, and other dates that need to land on the last day of a month. Use a positive value for months to move forward in time, and a negative number to move back in time. You can use EOMONTH to calculate expiration dates, due dates, and other dates that need to land on the last day of a month. The EOMONTH function takes two arguments: start_date and months. Start_date must be a valid Excel date. The months argument specifies how many months in the future or past to move – use a positive number to move forward in time, and a negative number to move back in time.

Arguments of EOMONTH Function:

• start_date - A date that represents the start date in a valid Excel serial number format.
• months - The number of months before or after start_date, 0 stands for same month.

WEEKNUM

WEEKNUM function in excel takes a date and returns a week number that corresponds to the week of year. The WEEKNUM function starts counting on the week that contains January 1. By default, weeks begin on Sunday, but this can be changed. The WEEKNUM function accepts two arguments, serial_num and return_type. The serial_num argument must have a valid Excel date. The return_type argument controls what day of the week begins a new week number. Return_type is optional and defaults to 1, which sets new week numbers to start on Sunday. When return_type is set to 2, week numbers begin on Monday (see the full list while applying the formula).

Arguments of WEEKNUM Function:

• serial_num - A valid Excel date in serial number format.
• return_type - [optional] The day the week begins. Default is 1.

WEEKDAY

WEEKDAY function takes a date and returns a number between 1-7 representing the day of week. By default, WEEKDAY returns 1 for Sunday and 7 for Saturday, but this is configurable. You can use the WEEKDAY function inside other formulas to check the day of week. The WEEKDAY function takes two arguments: serial_number and return_type. Serial_number should be a valid Excel date in serial number format. Return_type is an optional numeric code that controls which day of the week is considered the first day. By default, WEEKDAY returns 1 for Sunday and 7 for Saturday (see the full list while applying the formula).

Arguments of WEEKDAY Function:

• serial_number - The date for which you want to get the day of week.
• return_type - [optional] A number representing day of week mapping scheme. Default is 1.