WORKDAY.INTL

Calculates the date after a specified number of workdays excluding specified weekend days and holidays.

WORKDAY.INTL(DATE(1969, 7, 21), 4, 1, A1:A10)

WORKDAY.INTL(DATE(1995, 8, 13), -2, 2, B1:B10)

WORKDAY.INTL(DATE(1969, 7, 21), 0)

WORKDAY.INTL(start_date, num_days, [weekend], [holidays])

start_date - The date from which to begin counting.
num_days - The number of working days to advance from start_date. If negative, counts backwards.
weekend - [ OPTIONAL - 1 by default ] - A number or string representing which days of the week are considered weekends.
- String method: weekends can be specified using seven 0’s and 1’s, where the first number in the set represents Monday and the last number is for Sunday. A zero means that the day is a work day, a 1 means that the day is a weekend. For example, “0000011” would mean Saturday and Sunday are weekends.
- Number method: instead of using the string method above, a single number can be used. 1 = Saturday/Sunday are weekends, 2 = Sunday/Monday, and this pattern repeats until 7 = Friday/Saturday. 11 = Sunday is the only weekend, 12 = Monday is the only weekend, and this pattern repeats until 17 = Saturday is the only weekend.
holidays - [ OPTIONAL ] - A range or array constant containing the dates to consider holidays.

WORKDAY.INTL does not autoconvert number formats in the same way that Google Sheets does upon direct entry into cells. Therefore, WORKDAY.INTL(10/10/2000,4) is interpreted as WORKDAY.INTL(0.005,4), where the provided date is the quotient of 10 divided by 10 divided by 2000.
WORKDAY.INTL calculates a number of working days after a given date. To calculate the number of working days between two dates, use NETWORKDAYS.INTL.
WORKDAY.INTL works similarly to WORKDAY but also allows weekend days to be specified (for areas where Saturday and Sunday are not considered the weekend).

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