Weekday

Standard library enum · Returned by Date.weekday

A Weekday is a day of the week. A Date or a DateTime gives its weekday with weekday, and the seven values are written with the type’s name in front, as for any enum:

const day = Date(2026, 9, 25).weekday
print(day)
print(day == Weekday.friday)

Output

Friday
true

A weekday prints as its capitalized English name, which is how it appears when put into text.

The values

Value	Prints as
Weekday.monday	Monday
Weekday.tuesday	Tuesday
Weekday.wednesday	Wednesday
Weekday.thursday	Thursday
Weekday.friday	Friday
Weekday.saturday	Saturday
Weekday.sunday	Sunday

Comparing weekdays

Weekdays can be compared with == and used as dictionary keys, but they have no order and no number. A week is a cycle, and whether it starts on Sunday or Monday, or counts from 0 or 1, differs between countries and between programs. So Weekday.monday < Weekday.tuesday is an error, rather than a quiet choice of one convention. The values are listed Monday first, as in the international date standard, only to make them easy to read.

To ask about groups of days, use a case, which also makes sure every day is handled:

const day = Date(2026, 9, 26).weekday
const kind = case day {
    when Weekday.saturday, Weekday.sunday then "weekend"
    else then "weekday"
}
print(kind)

Output

weekend