Lesson#37: WORKDAY, WORKDAY.INTL is very essential for project scheduling

where,
start_date is the date from which to start. days is the working days before or after start_date.
holidays is optional, and a list of dates that should be considered non-work days.

By default, WORKDAY will exclude weekends (Saturday and Sunday)

Returns the serial number of the date before or after a specified number of workdays with custom weekend parameters.

Syntax of this function is WORKDAY.INTL(start_date, days, [weekend], [holidays]) wherestart_date is the start date.
days is the number of workdays before or after the start_date. A positive value yields a future date; a negative value yields a past date.
the weekend is optional. The setting for which days of the week should be considered weekends.
holidays is optional. A list of one or more dates that should be considered non-work days.

In the below chart, I have shown what will be the return value.

Weekend number	Weekend days
1 or omitted	Saturday, Sunday
2	Sunday, Monday
3	Monday, Tuesday
4	Tuesday, Wednesday
5	Wednesday, Thursday
6	Thursday, Friday
7	Friday, Saturday
11	Sunday only
12	Monday only
13	Tuesday only
14	Wednesday only
15	Thursday only
16	Friday only
17	Saturday only

There is another option which can modify weekend holidays.

Weekend string values are seven characters long and each character in the string represents a day of the week, starting with Monday. 1 represents a non-workday and 0 represents a workday. Only the characters 1 and 0 are permitted in the string.

Example:

=WORKDAYS.INTL(C2,D2,”1111111″,)	(star_date, end_date, “all seven days are weekend” [holiday omitted])
=WORKDAYS.INTL(C2,D2,”1101111″,)	(star_date, end_date, “only tuesday is working day” [holiday omitted])
=WORKDAYS.INTL(C2,D2,”1100001″,)	(star_date, end_date, “tuesday to friday are working day” [holiday omitted])
=WORKDAYS.INTL(C2,D2,”0000001″,)	(star_date, end_date, “only saturday is weekday” [holiday omitted])
=WORKDAYS.INTL(C2,D2,”0000000″,)	(star_date, end_date, “no weekend considered” [holiday omitted])