The WORKDAY function is a date and time function which returns the workday which falls the defined number of days before or after the initial date. It is possible to list holidays which are to be removed from any calculations. Workdays are defined as being Monday-Friday.

This is the format of the WORKDAY function:

=WORKDAY(INITIAL DATE, NUMBER OF DAYS, HOLIDAYS)

Here is an example of the WORKDAY function:

=WORKDAY( 2020-01-14, 5) = 2020-01-21 

This function is valuable when creating or providing estimates regarding time to complete or prepare for an event. As it calculates based on a standard five-day workweek, it is possible to use historical evidence to provide an approximation of when a task can occur based on the current date and its estimated duration.

An example of a functional implementation of this would be when creating a timeline for an event, every member of the team responsible has some experience or knowledge of the work required for the event to run smoothly. Working together plans are laid out detailing the tasks that need to be completed, and their approximate time to complete. By using WORKDAY, we can now organize these events in order and date them to see by when the event will be ready to launch.

=WORKDAY(Project start date, Days to complete task A)

=WORKDAY(Date of task A completion, Days to complete task B)

Etc…