Calendar.day_of_week
You're seeing just the callback
day_of_week
, go back to Calendar module for more information.
Specs
day_of_week(year(), month(), day(), starting_on :: :default | atom()) :: {day_of_week(), first_day_of_week :: non_neg_integer(), last_day_of_week :: non_neg_integer()}
Calculates the day of the week from the given year
, month
, and day
.
The starting_on
represents the starting day of the week. All
calendars must support at least the :default
value. They may
also support other values representing their days of the week.