Struct Date

pub struct Date { /* private fields */ }

Date in the proleptic Gregorian calendar.

By default, years between ±9999 inclusive are representable. This can be expanded to ±999,999 inclusive by enabling the large-dates crate feature. Doing so has performance implications and introduces some ambiguities when parsing.

Implementations

impl Date

pub const MIN: Self = _

The minimum valid Date.

The value of this may vary depending on the feature flags enabled.

pub const MAX: Self = _

The maximum valid Date.

The value of this may vary depending on the feature flags enabled.

pub const fn from_calendar_date( year: i32, month: Month, day: u8, ) -> Result<Self, ComponentRange>

Attempt to create a Date from the year, month, and day.

assert!(Date::from_calendar_date(2019, Month::January, 1).is_ok());
assert!(Date::from_calendar_date(2019, Month::December, 31).is_ok());

assert!(Date::from_calendar_date(2019, Month::February, 29).is_err()); // 2019 isn't a leap year.

pub const fn from_ordinal_date( year: i32, ordinal: u16, ) -> Result<Self, ComponentRange>

Attempt to create a Date from the year and ordinal day number.

assert!(Date::from_ordinal_date(2019, 1).is_ok());
assert!(Date::from_ordinal_date(2019, 365).is_ok());

assert!(Date::from_ordinal_date(2019, 366).is_err()); // 2019 isn't a leap year.

pub const fn from_iso_week_date( year: i32, week: u8, weekday: Weekday, ) -> Result<Self, ComponentRange>

Attempt to create a Date from the ISO year, week, and weekday.

assert!(Date::from_iso_week_date(2019, 1, Monday).is_ok());
assert!(Date::from_iso_week_date(2019, 1, Tuesday).is_ok());
assert!(Date::from_iso_week_date(2020, 53, Friday).is_ok());

assert!(Date::from_iso_week_date(2019, 53, Monday).is_err()); // 2019 doesn't have 53 weeks.

pub const fn from_julian_day(julian_day: i32) -> Result<Self, ComponentRange>

Create a Date from the Julian day.

The algorithm to perform this conversion is derived from one provided by Peter Baum; it is freely available here.

assert_eq!(Date::from_julian_day(0), Ok(date!(-4713 - 11 - 24)));
assert_eq!(Date::from_julian_day(2_451_545), Ok(date!(2000-01-01)));
assert_eq!(Date::from_julian_day(2_458_485), Ok(date!(2019-01-01)));
assert_eq!(Date::from_julian_day(2_458_849), Ok(date!(2019-12-31)));

pub const fn year(self) -> i32

Get the year of the date.

assert_eq!(date!(2019-01-01).year(), 2019);
assert_eq!(date!(2019-12-31).year(), 2019);
assert_eq!(date!(2020-01-01).year(), 2020);

pub const fn month(self) -> Month

Get the month.

assert_eq!(date!(2019-01-01).month(), Month::January);
assert_eq!(date!(2019-12-31).month(), Month::December);

pub const fn day(self) -> u8

Get the day of the month.

The returned value will always be in the range 1..=31.

assert_eq!(date!(2019-01-01).day(), 1);
assert_eq!(date!(2019-12-31).day(), 31);

pub const fn ordinal(self) -> u16

Get the day of the year.

The returned value will always be in the range 1..=366 (1..=365 for common years).

assert_eq!(date!(2019-01-01).ordinal(), 1);
assert_eq!(date!(2019-12-31).ordinal(), 365);

pub const fn iso_week(self) -> u8

Get the ISO week number.

The returned value will always be in the range 1..=53.

assert_eq!(date!(2019-01-01).iso_week(), 1);
assert_eq!(date!(2019-10-04).iso_week(), 40);
assert_eq!(date!(2020-01-01).iso_week(), 1);
assert_eq!(date!(2020-12-31).iso_week(), 53);
assert_eq!(date!(2021-01-01).iso_week(), 53);

pub const fn sunday_based_week(self) -> u8

Get the week number where week 1 begins on the first Sunday.

The returned value will always be in the range 0..=53.

assert_eq!(date!(2019-01-01).sunday_based_week(), 0);
assert_eq!(date!(2020-01-01).sunday_based_week(), 0);
assert_eq!(date!(2020-12-31).sunday_based_week(), 52);
assert_eq!(date!(2021-01-01).sunday_based_week(), 0);

pub const fn monday_based_week(self) -> u8

Get the week number where week 1 begins on the first Monday.

The returned value will always be in the range 0..=53.

assert_eq!(date!(2019-01-01).monday_based_week(), 0);
assert_eq!(date!(2020-01-01).monday_based_week(), 0);
assert_eq!(date!(2020-12-31).monday_based_week(), 52);
assert_eq!(date!(2021-01-01).monday_based_week(), 0);

pub const fn to_calendar_date(self) -> (i32, Month, u8)

Get the year, month, and day.

assert_eq!(
    date!(2019-01-01).to_calendar_date(),
    (2019, Month::January, 1)
);

pub const fn to_ordinal_date(self) -> (i32, u16)

Get the year and ordinal day number.

assert_eq!(date!(2019-01-01).to_ordinal_date(), (2019, 1));

pub const fn to_iso_week_date(self) -> (i32, u8, Weekday)

Get the ISO 8601 year, week number, and weekday.

assert_eq!(date!(2019-01-01).to_iso_week_date(), (2019, 1, Tuesday));
assert_eq!(date!(2019-10-04).to_iso_week_date(), (2019, 40, Friday));
assert_eq!(date!(2020-01-01).to_iso_week_date(), (2020, 1, Wednesday));
assert_eq!(date!(2020-12-31).to_iso_week_date(), (2020, 53, Thursday));
assert_eq!(date!(2021-01-01).to_iso_week_date(), (2020, 53, Friday));

pub const fn weekday(self) -> Weekday

Get the weekday.

assert_eq!(date!(2019-01-01).weekday(), Tuesday);
assert_eq!(date!(2019-02-01).weekday(), Friday);
assert_eq!(date!(2019-03-01).weekday(), Friday);
assert_eq!(date!(2019-04-01).weekday(), Monday);
assert_eq!(date!(2019-05-01).weekday(), Wednesday);
assert_eq!(date!(2019-06-01).weekday(), Saturday);
assert_eq!(date!(2019-07-01).weekday(), Monday);
assert_eq!(date!(2019-08-01).weekday(), Thursday);
assert_eq!(date!(2019-09-01).weekday(), Sunday);
assert_eq!(date!(2019-10-01).weekday(), Tuesday);
assert_eq!(date!(2019-11-01).weekday(), Friday);
assert_eq!(date!(2019-12-01).weekday(), Sunday);

pub const fn next_day(self) -> Option<Self>

Get the next calendar date.

assert_eq!(date!(2019-01-01).next_day(), Some(date!(2019-01-02)));
assert_eq!(date!(2019-01-31).next_day(), Some(date!(2019-02-01)));
assert_eq!(date!(2019-12-31).next_day(), Some(date!(2020-01-01)));
assert_eq!(Date::MAX.next_day(), None);

pub const fn previous_day(self) -> Option<Self>

Get the previous calendar date.

assert_eq!(date!(2019-01-02).previous_day(), Some(date!(2019-01-01)));
assert_eq!(date!(2019-02-01).previous_day(), Some(date!(2019-01-31)));
assert_eq!(date!(2020-01-01).previous_day(), Some(date!(2019-12-31)));
assert_eq!(Date::MIN.previous_day(), None);

pub const fn next_occurrence(self, weekday: Weekday) -> Self

Calculates the first occurrence of a weekday that is strictly later than a given Date.

Panics

Panics if an overflow occurred.

Examples

assert_eq!(
    date!(2023-06-28).next_occurrence(Weekday::Monday),
    date!(2023-07-03)
);
assert_eq!(
    date!(2023-06-19).next_occurrence(Weekday::Monday),
    date!(2023-06-26)
);

pub const fn prev_occurrence(self, weekday: Weekday) -> Self

Calculates the first occurrence of a weekday that is strictly earlier than a given Date.

Panics

Panics if an overflow occurred.

Examples

assert_eq!(
    date!(2023-06-28).prev_occurrence(Weekday::Monday),
    date!(2023-06-26)
);
assert_eq!(
    date!(2023-06-19).prev_occurrence(Weekday::Monday),
    date!(2023-06-12)
);

pub const fn nth_next_occurrence(self, weekday: Weekday, n: u8) -> Self

Calculates the nth occurrence of a weekday that is strictly later than a given Date.

Panics

Panics if an overflow occurred or if n == 0.

Examples

assert_eq!(
    date!(2023-06-25).nth_next_occurrence(Weekday::Monday, 5),
    date!(2023-07-24)
);
assert_eq!(
    date!(2023-06-26).nth_next_occurrence(Weekday::Monday, 5),
    date!(2023-07-31)
);

pub const fn nth_prev_occurrence(self, weekday: Weekday, n: u8) -> Self

Calculates the nth occurrence of a weekday that is strictly earlier than a given Date.

Panics

Panics if an overflow occurred or if n == 0.

Examples

assert_eq!(
    date!(2023-06-27).nth_prev_occurrence(Weekday::Monday, 3),
    date!(2023-06-12)
);
assert_eq!(
    date!(2023-06-26).nth_prev_occurrence(Weekday::Monday, 3),
    date!(2023-06-05)
);

pub const fn to_julian_day(self) -> i32

Get the Julian day for the date.

The algorithm to perform this conversion is derived from one provided by Peter Baum; it is freely available here.

assert_eq!(date!(-4713 - 11 - 24).to_julian_day(), 0);
assert_eq!(date!(2000-01-01).to_julian_day(), 2_451_545);
assert_eq!(date!(2019-01-01).to_julian_day(), 2_458_485);
assert_eq!(date!(2019-12-31).to_julian_day(), 2_458_849);

pub const fn checked_add(self, duration: Duration) -> Option<Self>

Computes self + duration, returning None if an overflow occurred.

assert_eq!(Date::MAX.checked_add(1.days()), None);
assert_eq!(Date::MIN.checked_add((-2).days()), None);
assert_eq!(
    date!(2020-12-31).checked_add(2.days()),
    Some(date!(2021-01-02))
);

Note

This function only takes whole days into account.

assert_eq!(Date::MAX.checked_add(23.hours()), Some(Date::MAX));
assert_eq!(Date::MIN.checked_add((-23).hours()), Some(Date::MIN));
assert_eq!(
    date!(2020-12-31).checked_add(23.hours()),
    Some(date!(2020-12-31))
);
assert_eq!(
    date!(2020-12-31).checked_add(47.hours()),
    Some(date!(2021-01-01))
);

pub const fn checked_add_std(self, duration: StdDuration) -> Option<Self>

Computes self + duration, returning None if an overflow occurred.

assert_eq!(Date::MAX.checked_add_std(1.std_days()), None);
assert_eq!(
    date!(2020-12-31).checked_add_std(2.std_days()),
    Some(date!(2021-01-02))
);

Note

This function only takes whole days into account.

assert_eq!(Date::MAX.checked_add_std(23.std_hours()), Some(Date::MAX));
assert_eq!(
    date!(2020-12-31).checked_add_std(23.std_hours()),
    Some(date!(2020-12-31))
);
assert_eq!(
    date!(2020-12-31).checked_add_std(47.std_hours()),
    Some(date!(2021-01-01))
);

pub const fn checked_sub(self, duration: Duration) -> Option<Self>

Computes self - duration, returning None if an overflow occurred.

assert_eq!(Date::MAX.checked_sub((-2).days()), None);
assert_eq!(Date::MIN.checked_sub(1.days()), None);
assert_eq!(
    date!(2020-12-31).checked_sub(2.days()),
    Some(date!(2020-12-29))
);

Note

This function only takes whole days into account.

assert_eq!(Date::MAX.checked_sub((-23).hours()), Some(Date::MAX));
assert_eq!(Date::MIN.checked_sub(23.hours()), Some(Date::MIN));
assert_eq!(
    date!(2020-12-31).checked_sub(23.hours()),
    Some(date!(2020-12-31))
);
assert_eq!(
    date!(2020-12-31).checked_sub(47.hours()),
    Some(date!(2020-12-30))
);

pub const fn checked_sub_std(self, duration: StdDuration) -> Option<Self>

Computes self - duration, returning None if an overflow occurred.

assert_eq!(Date::MIN.checked_sub_std(1.std_days()), None);
assert_eq!(
    date!(2020-12-31).checked_sub_std(2.std_days()),
    Some(date!(2020-12-29))
);

Note

This function only takes whole days into account.

assert_eq!(Date::MIN.checked_sub_std(23.std_hours()), Some(Date::MIN));
assert_eq!(
    date!(2020-12-31).checked_sub_std(23.std_hours()),
    Some(date!(2020-12-31))
);
assert_eq!(
    date!(2020-12-31).checked_sub_std(47.std_hours()),
    Some(date!(2020-12-30))
);

pub const fn saturating_add(self, duration: Duration) -> Self

Computes self + duration, saturating value on overflow.

assert_eq!(Date::MAX.saturating_add(1.days()), Date::MAX);
assert_eq!(Date::MIN.saturating_add((-2).days()), Date::MIN);
assert_eq!(
    date!(2020-12-31).saturating_add(2.days()),
    date!(2021-01-02)
);

Note

This function only takes whole days into account.

assert_eq!(
    date!(2020-12-31).saturating_add(23.hours()),
    date!(2020-12-31)
);
assert_eq!(
    date!(2020-12-31).saturating_add(47.hours()),
    date!(2021-01-01)
);

pub const fn saturating_sub(self, duration: Duration) -> Self

Computes self - duration, saturating value on overflow.

assert_eq!(Date::MAX.saturating_sub((-2).days()), Date::MAX);
assert_eq!(Date::MIN.saturating_sub(1.days()), Date::MIN);
assert_eq!(
    date!(2020-12-31).saturating_sub(2.days()),
    date!(2020-12-29)
);

Note

This function only takes whole days into account.

assert_eq!(
    date!(2020-12-31).saturating_sub(23.hours()),
    date!(2020-12-31)
);
assert_eq!(
    date!(2020-12-31).saturating_sub(47.hours()),
    date!(2020-12-30)
);

pub const fn replace_year(self, year: i32) -> Result<Self, ComponentRange>

Replace the year. The month and day will be unchanged.

assert_eq!(
    date!(2022-02-18).replace_year(2019),
    Ok(date!(2019-02-18))
);
assert!(date!(2022-02-18).replace_year(-1_000_000_000).is_err()); // -1_000_000_000 isn't a valid year
assert!(date!(2022-02-18).replace_year(1_000_000_000).is_err()); // 1_000_000_000 isn't a valid year

pub const fn replace_month(self, month: Month) -> Result<Self, ComponentRange>

Replace the month of the year.

assert_eq!(
    date!(2022-02-18).replace_month(Month::January),
    Ok(date!(2022-01-18))
);
assert!(date!(2022-01-30)
    .replace_month(Month::February)
    .is_err()); // 30 isn't a valid day in February

pub const fn replace_day(self, day: u8) -> Result<Self, ComponentRange>

Replace the day of the month.

assert_eq!(date!(2022-02-18).replace_day(1), Ok(date!(2022-02-01)));
assert!(date!(2022-02-18).replace_day(0).is_err()); // 0 isn't a valid day
assert!(date!(2022-02-18).replace_day(30).is_err()); // 30 isn't a valid day in February

pub const fn replace_ordinal(self, ordinal: u16) -> Result<Self, ComponentRange>

Replace the day of the year.

assert_eq!(date!(2022-049).replace_ordinal(1), Ok(date!(2022-001)));
assert!(date!(2022-049).replace_ordinal(0).is_err()); // 0 isn't a valid ordinal
assert!(date!(2022-049).replace_ordinal(366).is_err()); // 2022 isn't a leap year

impl Date

Methods to add a Time component, resulting in a PrimitiveDateTime.

pub const fn midnight(self) -> PrimitiveDateTime

Create a PrimitiveDateTime using the existing date. The Time component will be set to midnight.

assert_eq!(date!(1970-01-01).midnight(), datetime!(1970-01-01 0:00));

pub const fn with_time(self, time: Time) -> PrimitiveDateTime

Create a PrimitiveDateTime using the existing date and the provided Time.

assert_eq!(
    date!(1970-01-01).with_time(time!(0:00)),
    datetime!(1970-01-01 0:00),
);

pub const fn with_hms( self, hour: u8, minute: u8, second: u8, ) -> Result<PrimitiveDateTime, ComponentRange>

Attempt to create a PrimitiveDateTime using the existing date and the provided time.

assert!(date!(1970-01-01).with_hms(0, 0, 0).is_ok());
assert!(date!(1970-01-01).with_hms(24, 0, 0).is_err());

pub const fn with_hms_milli( self, hour: u8, minute: u8, second: u8, millisecond: u16, ) -> Result<PrimitiveDateTime, ComponentRange>

Attempt to create a PrimitiveDateTime using the existing date and the provided time.

assert!(date!(1970-01-01).with_hms_milli(0, 0, 0, 0).is_ok());
assert!(date!(1970-01-01).with_hms_milli(24, 0, 0, 0).is_err());

pub const fn with_hms_micro( self, hour: u8, minute: u8, second: u8, microsecond: u32, ) -> Result<PrimitiveDateTime, ComponentRange>

Attempt to create a PrimitiveDateTime using the existing date and the provided time.

assert!(date!(1970-01-01).with_hms_micro(0, 0, 0, 0).is_ok());
assert!(date!(1970-01-01).with_hms_micro(24, 0, 0, 0).is_err());

pub const fn with_hms_nano( self, hour: u8, minute: u8, second: u8, nanosecond: u32, ) -> Result<PrimitiveDateTime, ComponentRange>

Attempt to create a PrimitiveDateTime using the existing date and the provided time.

assert!(date!(1970-01-01).with_hms_nano(0, 0, 0, 0).is_ok());
assert!(date!(1970-01-01).with_hms_nano(24, 0, 0, 0).is_err());

impl Date

pub fn format_into( self, output: &mut impl Write, format: &(impl Formattable + ?Sized), ) -> Result<usize, Format>

Available on crate feature formatting only.

Format the Date using the provided format description.

pub fn format( self, format: &(impl Formattable + ?Sized), ) -> Result<String, Format>

Available on crate feature formatting only.

Format the Date using the provided format description.

let format = format_description::parse("[year]-[month]-[day]")?;
assert_eq!(date!(2020-01-02).format(&format)?, "2020-01-02");

impl Date

pub fn parse( input: &str, description: &(impl Parsable + ?Sized), ) -> Result<Self, Parse>

Available on crate feature parsing only.

Parse a Date from the input using the provided format description.

let format = format_description!("[year]-[month]-[day]");
assert_eq!(Date::parse("2020-01-02", &format)?, date!(2020-01-02));

Trait Implementations

impl Add<Duration> for Date

fn add(self, duration: Duration) -> Self::Output

Panics

This may panic if an overflow occurs.

type Output = Date

The resulting type after applying the + operator.

impl Add<Duration> for Date

fn add(self, duration: StdDuration) -> Self::Output

Panics

This may panic if an overflow occurs.

type Output = Date

The resulting type after applying the + operator.

impl AddAssign<Duration> for Date

fn add_assign(&mut self, rhs: Duration)

Performs the += operation.

impl AddAssign<Duration> for Date

fn add_assign(&mut self, rhs: StdDuration)

Performs the += operation.

impl Clone for Date

fn clone(&self) -> Date

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Date

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Display for Date

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for Date

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Date

fn cmp(&self, other: &Date) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Date

fn eq(&self, other: &Date) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Date

fn partial_cmp(&self, other: &Date) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl SmartDisplay for Date

type Metadata = DateMetadata

User-provided metadata type.

fn metadata(&self, _: FormatterOptions) -> Metadata<'_, Self>

Compute any information needed to format the value. This must, at a minimum, determine the width of the value before any padding is added by the formatter.

fn fmt_with_metadata( &self, f: &mut Formatter<'_>, metadata: Metadata<'_, Self>, ) -> Result

Format the value using the given formatter and metadata. The formatted output should have the width indicated by the metadata. This is before any padding is added by the formatter.

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Format the value using the given formatter. This is the same as Display::fmt.

impl Sub<Duration> for Date

fn sub(self, duration: Duration) -> Self::Output

Panics

This may panic if an overflow occurs.

type Output = Date

The resulting type after applying the - operator.

impl Sub<Duration> for Date

fn sub(self, duration: StdDuration) -> Self::Output

Panics

This may panic if an overflow occurs.

type Output = Date

The resulting type after applying the - operator.

impl Sub for Date

type Output = Duration

The resulting type after applying the - operator.

fn sub(self, other: Self) -> Self::Output

Performs the - operation.

impl SubAssign<Duration> for Date

fn sub_assign(&mut self, rhs: Duration)

Performs the -= operation.

impl SubAssign<Duration> for Date

fn sub_assign(&mut self, rhs: StdDuration)

Performs the -= operation.

impl TryFrom<Parsed> for Date

Available on crate feature parsing only.

type Error = TryFromParsed

The type returned in the event of a conversion error.

fn try_from(parsed: Parsed) -> Result<Self, Self::Error>

Performs the conversion.

impl Copy for Date

impl Eq for Date

impl StructuralPartialEq for Date