Class Date

src/pendulum/date.py:34–757

class Date(FormattableMixin, date):
    _MODIFIERS_VALID_UNITS: ClassVar[list[str]] = [
        "day",
        "week",
        "month",
        "year",
        "decade",
        "century",
    ]

    # Getters/Setters

    def set(
        self, year: int | None = None, month: int | None = None, day: int | None = None
    ) -> Self:
        return self.replace(year=year, month=month, day=day)

    @property
    def day_of_week(self) -> WeekDay:
        """
        Returns the day of the week (0-6).
        """
        return WeekDay(self.weekday())

    @property
    def day_of_year(self) -> int:
        """
        Returns the day of the year (1-366).
        """
        k = 1 if self.is_leap_year() else 2

        return (275 * self.month) // 9 - k * ((self.month + 9) // 12) + self.day - 30

    @property
    def week_of_year(self) -> int:
        return self.isocalendar()[1]

    @property
    def days_in_month(self) -> int:
        return calendar.monthrange(self.year, self.month)[1]

    @property
    def week_of_month(self) -> int:
        return math.ceil((self.day + self.first_of("month").isoweekday() - 1) / 7)

    @property
    def age(self) -> int:
        return self.diff(abs=False).in_years()

    @property
    def quarter(self) -> int:
        return math.ceil(self.month / 3)

    # String Formatting

    def to_date_string(self) -> str:
        """
        Format the instance as date.