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//! The [`Date`] struct and its associated `impl`s.
use core::fmt;
use core::ops::{Add, Sub};
use core::time::Duration as StdDuration;
#[cfg(feature = "formatting")]
use std::io;
use crate::convert::*;
#[cfg(feature = "formatting")]
use crate::formatting::Formattable;
#[cfg(feature = "parsing")]
use crate::parsing::Parsable;
use crate::util::{days_in_year, days_in_year_month, is_leap_year, weeks_in_year};
use crate::{error, Duration, Month, PrimitiveDateTime, Time, Weekday};
/// The minimum valid year.
pub(crate) const MIN_YEAR: i32 = if cfg!(feature = "large-dates") {
-999_999
} else {
-9999
};
/// The maximum valid year.
pub(crate) const MAX_YEAR: i32 = if cfg!(feature = "large-dates") {
999_999
} else {
9999
};
/// 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.
#[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
pub struct Date {
/// Bitpacked field containing both the year and ordinal.
// | xx | xxxxxxxxxxxxxxxxxxxxx | xxxxxxxxx |
// | 2 bits | 21 bits | 9 bits |
// | unassigned | year | ordinal |
// The year is 15 bits when `large-dates` is not enabled.
value: i32,
}
impl Date {
/// The minimum valid `Date`.
///
/// The value of this may vary depending on the feature flags enabled.
pub const MIN: Self = Self::__from_ordinal_date_unchecked(MIN_YEAR, 1);
/// The maximum valid `Date`.
///
/// The value of this may vary depending on the feature flags enabled.
pub const MAX: Self = Self::__from_ordinal_date_unchecked(MAX_YEAR, days_in_year(MAX_YEAR));
// region: constructors
/// Construct a `Date` from the year and ordinal values, the validity of which must be
/// guaranteed by the caller.
#[doc(hidden)]
pub const fn __from_ordinal_date_unchecked(year: i32, ordinal: u16) -> Self {
debug_assert!(year >= MIN_YEAR);
debug_assert!(year <= MAX_YEAR);
debug_assert!(ordinal != 0);
debug_assert!(ordinal <= days_in_year(year));
Self {
value: (year << 9) | ordinal as i32,
}
}
/// Attempt to create a `Date` from the year, month, and day.
///
/// ```rust
/// # use time::{Date, Month};
/// assert!(Date::from_calendar_date(2019, Month::January, 1).is_ok());
/// assert!(Date::from_calendar_date(2019, Month::December, 31).is_ok());
/// ```
///
/// ```rust
/// # use time::{Date, Month};
/// assert!(Date::from_calendar_date(2019, Month::February, 29).is_err()); // 2019 isn't a leap year.
/// ```
pub const fn from_calendar_date(
year: i32,
month: Month,
day: u8,
) -> Result<Self, error::ComponentRange> {
/// Cumulative days through the beginning of a month in both common and leap years.
const DAYS_CUMULATIVE_COMMON_LEAP: [[u16; 12]; 2] = [
[0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334],
[0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335],
];
ensure_value_in_range!(year in MIN_YEAR => MAX_YEAR);
ensure_value_in_range!(day conditionally in 1 => days_in_year_month(year, month));
Ok(Self::__from_ordinal_date_unchecked(
year,
DAYS_CUMULATIVE_COMMON_LEAP[is_leap_year(year) as usize][month as usize - 1]
+ day as u16,
))
}
/// Attempt to create a `Date` from the year and ordinal day number.
///
/// ```rust
/// # use time::Date;
/// assert!(Date::from_ordinal_date(2019, 1).is_ok());
/// assert!(Date::from_ordinal_date(2019, 365).is_ok());
/// ```
///
/// ```rust
/// # use time::Date;
/// assert!(Date::from_ordinal_date(2019, 366).is_err()); // 2019 isn't a leap year.
/// ```
pub const fn from_ordinal_date(year: i32, ordinal: u16) -> Result<Self, error::ComponentRange> {
ensure_value_in_range!(year in MIN_YEAR => MAX_YEAR);
ensure_value_in_range!(ordinal conditionally in 1 => days_in_year(year));
Ok(Self::__from_ordinal_date_unchecked(year, ordinal))
}
/// Attempt to create a `Date` from the ISO year, week, and weekday.
///
/// ```rust
/// # use time::{Date, 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());
/// ```
///
/// ```rust
/// # use time::{Date, Weekday::*};
/// assert!(Date::from_iso_week_date(2019, 53, Monday).is_err()); // 2019 doesn't have 53 weeks.
/// ```
pub const fn from_iso_week_date(
year: i32,
week: u8,
weekday: Weekday,
) -> Result<Self, error::ComponentRange> {
ensure_value_in_range!(year in MIN_YEAR => MAX_YEAR);
ensure_value_in_range!(week conditionally in 1 => weeks_in_year(year));
let adj_year = year - 1;
let raw = 365 * adj_year + div_floor!(adj_year, 4) - div_floor!(adj_year, 100)
+ div_floor!(adj_year, 400);
let jan_4 = match (raw % 7) as i8 {
-6 | 1 => 8,
-5 | 2 => 9,
-4 | 3 => 10,
-3 | 4 => 4,
-2 | 5 => 5,
-1 | 6 => 6,
_ => 7,
};
let ordinal = week as i16 * 7 + weekday.number_from_monday() as i16 - jan_4;
Ok(if ordinal <= 0 {
Self::__from_ordinal_date_unchecked(
year - 1,
(ordinal as u16).wrapping_add(days_in_year(year - 1)),
)
} else if ordinal > days_in_year(year) as i16 {
Self::__from_ordinal_date_unchecked(year + 1, ordinal as u16 - days_in_year(year))
} else {
Self::__from_ordinal_date_unchecked(year, ordinal as _)
})
}
/// Create a `Date` from the Julian day.
///
/// The algorithm to perform this conversion is derived from one provided by Peter Baum; it is
///
/// ```rust
/// # use time::Date;
/// # use time_macros::date;
/// 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)));
/// ```
#[doc(alias = "from_julian_date")]
pub const fn from_julian_day(julian_day: i32) -> Result<Self, error::ComponentRange> {
ensure_value_in_range!(
julian_day in Self::MIN.to_julian_day() => Self::MAX.to_julian_day()
);
Ok(Self::from_julian_day_unchecked(julian_day))
}
/// Create a `Date` from the Julian day.
///
/// This does not check the validity of the provided Julian day, and as such may result in an
/// internally invalid value.
#[doc(alias = "from_julian_date_unchecked")]
pub(crate) const fn from_julian_day_unchecked(julian_day: i32) -> Self {
debug_assert!(julian_day >= Self::MIN.to_julian_day());
debug_assert!(julian_day <= Self::MAX.to_julian_day());
// To avoid a potential overflow, the value may need to be widened for some arithmetic.
let z = julian_day - 1_721_119;
let (mut year, mut ordinal) = if julian_day < -19_752_948 || julian_day > 23_195_514 {
let g = 100 * z as i64 - 25;
let a = (g / 3_652_425) as i32;
let b = a - a / 4;
let year = div_floor!(100 * b as i64 + g, 36525) as i32;
let ordinal = (b + z - div_floor!(36525 * year as i64, 100) as i32) as _;
(year, ordinal)
} else {
let g = 100 * z - 25;
let a = g / 3_652_425;
let b = a - a / 4;
let year = div_floor!(100 * b + g, 36525);
let ordinal = (b + z - div_floor!(36525 * year, 100)) as _;
(year, ordinal)
};
if is_leap_year(year) {
ordinal += 60;
cascade!(ordinal in 1..367 => year);
} else {
ordinal += 59;
cascade!(ordinal in 1..366 => year);
}
Self::__from_ordinal_date_unchecked(year, ordinal)
}
// endregion constructors
// region: getters
/// Get the year of the date.
///
/// ```rust
/// # use time_macros::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 year(self) -> i32 {
self.value >> 9
}
/// Get the month.
///
/// ```rust
/// # use time::Month;
/// # use time_macros::date;
/// assert_eq!(date!(2019 - 01 - 01).month(), Month::January);
/// assert_eq!(date!(2019 - 12 - 31).month(), Month::December);
/// ```
pub const fn month(self) -> Month {
self.month_day().0
}
/// Get the day of the month.
///
/// The returned value will always be in the range `1..=31`.
///
/// ```rust
/// # use time_macros::date;
/// assert_eq!(date!(2019 - 01 - 01).day(), 1);
/// assert_eq!(date!(2019 - 12 - 31).day(), 31);
/// ```
pub const fn day(self) -> u8 {
self.month_day().1
}
/// Get the month and day. This is more efficient than fetching the components individually.
// For whatever reason, rustc has difficulty optimizing this function. It's significantly faster
// to write the statements out by hand.
pub(crate) const fn month_day(self) -> (Month, u8) {
/// The number of days up to and including the given month. Common years
/// are first, followed by leap years.
const CUMULATIVE_DAYS_IN_MONTH_COMMON_LEAP: [[u16; 11]; 2] = [
[31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334],
[31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335],
];
let days = CUMULATIVE_DAYS_IN_MONTH_COMMON_LEAP[is_leap_year(self.year()) as usize];
let ordinal = self.ordinal();
if ordinal > days[10] {
(Month::December, (ordinal - days[10]) as _)
} else if ordinal > days[9] {
(Month::November, (ordinal - days[9]) as _)
} else if ordinal > days[8] {
(Month::October, (ordinal - days[8]) as _)
} else if ordinal > days[7] {
(Month::September, (ordinal - days[7]) as _)
} else if ordinal > days[6] {
(Month::August, (ordinal - days[6]) as _)
} else if ordinal > days[5] {
(Month::July, (ordinal - days[5]) as _)
} else if ordinal > days[4] {
(Month::June, (ordinal - days[4]) as _)
} else if ordinal > days[3] {
(Month::May, (ordinal - days[3]) as _)
} else if ordinal > days[2] {
(Month::April, (ordinal - days[2]) as _)
} else if ordinal > days[1] {
(Month::March, (ordinal - days[1]) as _)
} else if ordinal > days[0] {
(Month::February, (ordinal - days[0]) as _)
} else {
(Month::January, ordinal as _)
}
}
/// Get the day of the year.
///
/// The returned value will always be in the range `1..=366` (`1..=365` for common years).
///
/// ```rust
/// # use time_macros::date;
/// assert_eq!(date!(2019 - 01 - 01).ordinal(), 1);
/// assert_eq!(date!(2019 - 12 - 31).ordinal(), 365);
/// ```
pub const fn ordinal(self) -> u16 {
(self.value & 0x1FF) as _
}
/// Get the ISO 8601 year and week number.
pub(crate) const fn iso_year_week(self) -> (i32, u8) {
let (year, ordinal) = self.to_ordinal_date();
match ((ordinal + 10 - self.weekday().number_from_monday() as u16) / 7) as _ {
0 => (year - 1, weeks_in_year(year - 1)),
53 if weeks_in_year(year) == 52 => (year + 1, 1),
week => (year, week),
}
}
/// Get the ISO week number.
///
/// The returned value will always be in the range `1..=53`.
///
/// ```rust
/// # use time_macros::date;
/// 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 iso_week(self) -> u8 {
self.iso_year_week().1
}
/// Get the week number where week 1 begins on the first Sunday.
///
/// The returned value will always be in the range `0..=53`.
///
/// ```rust
/// # use time_macros::date;
/// 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 sunday_based_week(self) -> u8 {
((self.ordinal() as i16 - self.weekday().number_days_from_sunday() as i16 + 6) / 7) as _
}
/// Get the week number where week 1 begins on the first Monday.
///
/// The returned value will always be in the range `0..=53`.
///
/// ```rust
/// # use time_macros::date;
/// 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 monday_based_week(self) -> u8 {
((self.ordinal() as i16 - self.weekday().number_days_from_monday() as i16 + 6) / 7) as _
}
/// Get the year, month, and day.
///
/// ```rust
/// # use time::Month;
/// # use time_macros::date;
/// assert_eq!(
/// date!(2019 - 01 - 01).to_calendar_date(),
/// (2019, Month::January, 1)
/// );
/// ```
pub const fn to_calendar_date(self) -> (i32, Month, u8) {
let (month, day) = self.month_day();
(self.year(), month, day)
}
/// Get the year and ordinal day number.
///
/// ```rust
/// # use time_macros::date;
/// assert_eq!(date!(2019 - 01 - 01).to_ordinal_date(), (2019, 1));
/// ```
pub const fn to_ordinal_date(self) -> (i32, u16) {
(self.year(), self.ordinal())
}
/// Get the ISO 8601 year, week number, and weekday.
///
/// ```rust
/// # use time::Weekday::*;
/// # use time_macros::date;
/// 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 to_iso_week_date(self) -> (i32, u8, Weekday) {
let (year, ordinal) = self.to_ordinal_date();
let weekday = self.weekday();
match ((ordinal + 10 - self.weekday().number_from_monday() as u16) / 7) as _ {
0 => (year - 1, weeks_in_year(year - 1), weekday),
53 if weeks_in_year(year) == 52 => (year + 1, 1, weekday),
week => (year, week, weekday),
}
}
/// Get the weekday.
///
/// ```rust
/// # use time::Weekday::*;
/// # use time_macros::date;
/// 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 weekday(self) -> Weekday {
match self.to_julian_day() % 7 {
-6 | 1 => Weekday::Tuesday,
-5 | 2 => Weekday::Wednesday,
-4 | 3 => Weekday::Thursday,
-3 | 4 => Weekday::Friday,
-2 | 5 => Weekday::Saturday,
-1 | 6 => Weekday::Sunday,
val => {
debug_assert!(val == 0);
Weekday::Monday
}
}
}
/// Get the next calendar date.
///
/// ```rust
/// # use time::Date;
/// # use time_macros::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 next_day(self) -> Option<Self> {
if self.ordinal() == 366 || (self.ordinal() == 365 && !is_leap_year(self.year())) {
if self.value == Self::MAX.value {
None
} else {
Some(Self::__from_ordinal_date_unchecked(self.year() + 1, 1))
}
} else {
Some(Self {
value: self.value + 1,
})
}
}
/// Get the previous calendar date.
///
/// ```rust
/// # use time::Date;
/// # use time_macros::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 previous_day(self) -> Option<Self> {
if self.ordinal() != 1 {
Some(Self {
value: self.value - 1,
})
} else if self.value == Self::MIN.value {
None
} else {
Some(Self::__from_ordinal_date_unchecked(
self.year() - 1,
days_in_year(self.year() - 1),
))
}
}
/// Calculates the first occurrence of a weekday that is strictly later than a given `Date`.
///
/// # Panics
/// Panics if an overflow occurred.
///
/// # Examples
/// ```
/// # use time::Weekday;
/// # use time_macros::date;
/// 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 next_occurrence(self, weekday: Weekday) -> Self {
expect_opt!(
self.checked_next_occurrence(weekday),
"overflow calculating the next occurrence of a weekday"
)
}
/// Calculates the first occurrence of a weekday that is strictly earlier than a given `Date`.
///
/// # Panics
/// Panics if an overflow occurred.
///
/// # Examples
/// ```
/// # use time::Weekday;
/// # use time_macros::date;
/// 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 prev_occurrence(self, weekday: Weekday) -> Self {
expect_opt!(
self.checked_prev_occurrence(weekday),
"overflow calculating the previous occurrence of a weekday"
)
}
/// Calculates the `n`th occurrence of a weekday that is strictly later than a given `Date`.
///
/// # Panics
/// Panics if an overflow occurred or if `n == 0`.
///
/// # Examples
/// ```
/// # use time::Weekday;
/// # use time_macros::date;
/// 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_next_occurrence(self, weekday: Weekday, n: u8) -> Self {
expect_opt!(
self.checked_nth_next_occurrence(weekday, n),
"overflow calculating the next occurrence of a weekday"
)
}
/// Calculates the `n`th occurrence of a weekday that is strictly earlier than a given `Date`.
///
/// # Panics
/// Panics if an overflow occurred or if `n == 0`.
///
/// # Examples
/// ```
/// # use time::Weekday;
/// # use time_macros::date;
/// 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 nth_prev_occurrence(self, weekday: Weekday, n: u8) -> Self {
expect_opt!(
self.checked_nth_prev_occurrence(weekday, n),
"overflow calculating the previous occurrence of a weekday"
)
}
/// Get the Julian day for the date.
///
/// The algorithm to perform this conversion is derived from one provided by Peter Baum; it is
///
/// ```rust
/// # use time_macros::date;
/// 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 to_julian_day(self) -> i32 {
let year = self.year() - 1;
let ordinal = self.ordinal() as i32;
ordinal + 365 * year + div_floor!(year, 4) - div_floor!(year, 100)
+ div_floor!(year, 400)
+ 1_721_425
}
// endregion getters
// region: checked arithmetic
/// Computes `self + duration`, returning `None` if an overflow occurred.
///
/// ```rust
/// # use time::{Date, ext::NumericalDuration};
/// # use time_macros::date;
/// 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.
///
/// ```rust
/// # use time::{Date, ext::NumericalDuration};
/// # use time_macros::date;
/// 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(self, duration: Duration) -> Option<Self> {
let whole_days = duration.whole_days();
if whole_days < i32::MIN as i64 || whole_days > i32::MAX as i64 {
return None;
}
let julian_day = const_try_opt!(self.to_julian_day().checked_add(whole_days as _));
if let Ok(date) = Self::from_julian_day(julian_day) {
Some(date)
} else {
None
}
}
/// Computes `self - duration`, returning `None` if an overflow occurred.
///
/// ```
/// # use time::{Date, ext::NumericalDuration};
/// # use time_macros::date;
/// 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.
///
/// ```
/// # use time::{Date, ext::NumericalDuration};
/// # use time_macros::date;
/// 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(self, duration: Duration) -> Option<Self> {
let whole_days = duration.whole_days();
if whole_days < i32::MIN as i64 || whole_days > i32::MAX as i64 {
return None;
}
let julian_day = const_try_opt!(self.to_julian_day().checked_sub(whole_days as _));
if let Ok(date) = Self::from_julian_day(julian_day) {
Some(date)
} else {
None
}
}
/// Calculates the first occurrence of a weekday that is strictly later than a given `Date`.
/// Returns `None` if an overflow occurred.
pub(crate) const fn checked_next_occurrence(self, weekday: Weekday) -> Option<Self> {
let day_diff = match weekday as i8 - self.weekday() as i8 {
1 | -6 => 1,
2 | -5 => 2,
3 | -4 => 3,
4 | -3 => 4,
5 | -2 => 5,
6 | -1 => 6,
val => {
debug_assert!(val == 0);
7
}
};
self.checked_add(Duration::days(day_diff))
}
/// Calculates the first occurrence of a weekday that is strictly earlier than a given `Date`.
/// Returns `None` if an overflow occurred.
pub(crate) const fn checked_prev_occurrence(self, weekday: Weekday) -> Option<Self> {
let day_diff = match weekday as i8 - self.weekday() as i8 {
1 | -6 => 6,
2 | -5 => 5,
3 | -4 => 4,
4 | -3 => 3,
5 | -2 => 2,
6 | -1 => 1,
val => {
debug_assert!(val == 0);
7
}
};
self.checked_sub(Duration::days(day_diff))
}
/// Calculates the `n`th occurrence of a weekday that is strictly later than a given `Date`.
/// Returns `None` if an overflow occurred or if `n == 0`.
pub(crate) const fn checked_nth_next_occurrence(self, weekday: Weekday, n: u8) -> Option<Self> {
if n == 0 {
return None;
}
let next_occ = self.checked_next_occurrence(weekday);
if let Some(val) = next_occ {
val.checked_add(Duration::weeks(n as i64 - 1))
} else {
None
}
}
/// Calculates the `n`th occurrence of a weekday that is strictly earlier than a given `Date`.
/// Returns `None` if an overflow occurred or if `n == 0`.
pub(crate) const fn checked_nth_prev_occurrence(self, weekday: Weekday, n: u8) -> Option<Self> {
if n == 0 {
return None;
}
let next_occ = self.checked_prev_occurrence(weekday);
if let Some(val) = next_occ {
val.checked_sub(Duration::weeks(n as i64 - 1))
} else {
None
}
}
// endregion: checked arithmetic
// region: saturating arithmetic
/// Computes `self + duration`, saturating value on overflow.
///
/// ```rust
/// # use time::{Date, ext::NumericalDuration};
/// # use time_macros::date;
/// 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.
///
/// ```rust
/// # use time::ext::NumericalDuration;
/// # use time_macros::date;
/// 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_add(self, duration: Duration) -> Self {
if let Some(datetime) = self.checked_add(duration) {
datetime
} else if duration.is_negative() {
Self::MIN
} else {
debug_assert!(duration.is_positive());
Self::MAX
}
}
/// Computes `self - duration`, saturating value on overflow.
///
/// ```
/// # use time::{Date, ext::NumericalDuration};
/// # use time_macros::date;
/// 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.
///
/// ```
/// # use time::ext::NumericalDuration;
/// # use time_macros::date;
/// 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 saturating_sub(self, duration: Duration) -> Self {
if let Some(datetime) = self.checked_sub(duration) {
datetime
} else if duration.is_negative() {
Self::MAX
} else {
debug_assert!(duration.is_positive());
Self::MIN
}
}
// region: saturating arithmetic
// region: replacement
/// Replace the year. The month and day will be unchanged.
///
/// ```rust
/// # use time_macros::date;
/// 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
/// ```
#[must_use = "This method does not mutate the original `Date`."]
pub const fn replace_year(self, year: i32) -> Result<Self, error::ComponentRange> {
ensure_value_in_range!(year in MIN_YEAR => MAX_YEAR);
let ordinal = self.ordinal();
// Dates in January and February are unaffected by leap years.
if ordinal <= 59 {
return Ok(Self::__from_ordinal_date_unchecked(year, ordinal));
}
match (is_leap_year(self.year()), is_leap_year(year)) {
(false, false) | (true, true) => Ok(Self::__from_ordinal_date_unchecked(year, ordinal)),
// February 29 does not exist in common years.
(true, false) if ordinal == 60 => Err(error::ComponentRange {
name: "day",
value: 29,
minimum: 1,
maximum: 28,
conditional_range: true,
}),
// We're going from a common year to a leap year. Shift dates in March and later by
// one day.
(false, true) => Ok(Self::__from_ordinal_date_unchecked(year, ordinal + 1)),
// We're going from a leap year to a common year. Shift dates in January and
// February by one day.
(true, false) => Ok(Self::__from_ordinal_date_unchecked(year, ordinal - 1)),
}
}
/// Replace the month of the year.
///
/// ```rust
/// # use time_macros::date;
/// # use time::Month;
/// 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
/// ```
#[must_use = "This method does not mutate the original `Date`."]
pub const fn replace_month(self, month: Month) -> Result<Self, error::ComponentRange> {
let (year, _, day) = self.to_calendar_date();
Self::from_calendar_date(year, month, day)
}
/// Replace the day of the month.
///
/// ```rust
/// # use time_macros::date;
/// 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
/// ```
#[must_use = "This method does not mutate the original `Date`."]
pub const fn replace_day(self, day: u8) -> Result<Self, error::ComponentRange> {
// Days 1-28 are present in every month, so we can skip checking.
if day == 0 || day >= 29 {
ensure_value_in_range!(
day conditionally in 1 => days_in_year_month(self.year(), self.month())
);
}
Ok(Self::__from_ordinal_date_unchecked(
self.year(),
(self.ordinal() as i16 - self.day() as i16 + day as i16) as _,
))
}
// endregion replacement
}
// region: attach time
/// Methods to add a [`Time`] component, resulting in a [`PrimitiveDateTime`].
impl Date {
/// Create a [`PrimitiveDateTime`] using the existing date. The [`Time`] component will be set
/// to midnight.
///
/// ```rust
/// # use time_macros::{date, datetime};
/// assert_eq!(date!(1970-01-01).midnight(), datetime!(1970-01-01 0:00));
/// ```
pub const fn midnight(self) -> PrimitiveDateTime {
PrimitiveDateTime::new(self, Time::MIDNIGHT)
}
/// Create a [`PrimitiveDateTime`] using the existing date and the provided [`Time`].
///
/// ```rust
/// # use time_macros::{date, datetime, time};
/// assert_eq!(
/// date!(1970-01-01).with_time(time!(0:00)),
/// datetime!(1970-01-01 0:00),
/// );
/// ```
pub const fn with_time(self, time: Time) -> PrimitiveDateTime {
PrimitiveDateTime::new(self, time)
}
/// Attempt to create a [`PrimitiveDateTime`] using the existing date and the provided time.
///
/// ```rust
/// # use time_macros::date;
/// 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(
self,
hour: u8,
minute: u8,
second: u8,
) -> Result<PrimitiveDateTime, error::ComponentRange> {
Ok(PrimitiveDateTime::new(
self,
const_try!(Time::from_hms(hour, minute, second)),
))
}
/// Attempt to create a [`PrimitiveDateTime`] using the existing date and the provided time.
///
/// ```rust
/// # use time_macros::date;
/// 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_milli(
self,
hour: u8,
minute: u8,
second: u8,
millisecond: u16,
) -> Result<PrimitiveDateTime, error::ComponentRange> {
Ok(PrimitiveDateTime::new(
self,
const_try!(Time::from_hms_milli(hour, minute, second, millisecond)),
))
}
/// Attempt to create a [`PrimitiveDateTime`] using the existing date and the provided time.
///
/// ```rust
/// # use time_macros::date;
/// 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_micro(
self,
hour: u8,
minute: u8,
second: u8,
microsecond: u32,
) -> Result<PrimitiveDateTime, error::ComponentRange> {
Ok(PrimitiveDateTime::new(
self,
const_try!(Time::from_hms_micro(hour, minute, second, microsecond)),
))
}
/// Attempt to create a [`PrimitiveDateTime`] using the existing date and the provided time.
///
/// ```rust
/// # use time_macros::date;
/// 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());
/// ```
pub const fn with_hms_nano(
self,
hour: u8,
minute: u8,
second: u8,
nanosecond: u32,
) -> Result<PrimitiveDateTime, error::ComponentRange> {
Ok(PrimitiveDateTime::new(
self,
const_try!(Time::from_hms_nano(hour, minute, second, nanosecond)),
))
}
}
// endregion attach time
// region: formatting & parsing
#[cfg(feature = "formatting")]
impl Date {
/// Format the `Date` using the provided [format description](crate::format_description).
pub fn format_into(
self,
output: &mut impl io::Write,
format: &(impl Formattable + ?Sized),
) -> Result<usize, error::Format> {
format.format_into(output, Some(self), None, None)
}
/// Format the `Date` using the provided [format description](crate::format_description).
///
/// ```rust
/// # use time::{format_description};
/// # use time_macros::date;
/// let format = format_description::parse("[year]-[month]-[day]")?;
/// assert_eq!(date!(2020 - 01 - 02).format(&format)?, "2020-01-02");
/// # Ok::<_, time::Error>(())
/// ```
pub fn format(self, format: &(impl Formattable + ?Sized)) -> Result<String, error::Format> {
format.format(Some(self), None, None)
}
}
#[cfg(feature = "parsing")]
impl Date {
/// Parse a `Date` from the input using the provided [format
/// description](crate::format_description).
///
/// ```rust
/// # use time::Date;
/// # use time_macros::{date, format_description};
/// let format = format_description!("[year]-[month]-[day]");
/// assert_eq!(Date::parse("2020-01-02", &format)?, date!(2020 - 01 - 02));
/// # Ok::<_, time::Error>(())
/// ```
pub fn parse(
input: &str,
description: &(impl Parsable + ?Sized),
) -> Result<Self, error::Parse> {
description.parse_date(input.as_bytes())
}
}
impl fmt::Display for Date {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
if cfg!(feature = "large-dates") && self.year().abs() >= 10_000 {
write!(
f,
"{:+}-{:02}-{:02}",
self.year(),
self.month() as u8,
self.day()
)
} else {
write!(
f,
"{:0width$}-{:02}-{:02}",
self.year(),
self.month() as u8,
self.day(),
width = 4 + (self.year() < 0) as usize
)
}
}
}
impl fmt::Debug for Date {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
fmt::Display::fmt(self, f)
}
}
// endregion formatting & parsing
// region: trait impls
impl Add<Duration> for Date {
type Output = Self;
fn add(self, duration: Duration) -> Self::Output {
self.checked_add(duration)
.expect("overflow adding duration to date")
}
}
impl Add<StdDuration> for Date {
type Output = Self;
fn add(self, duration: StdDuration) -> Self::Output {
Self::from_julian_day(
self.to_julian_day() + (duration.as_secs() / Second.per(Day) as u64) as i32,
)
.expect("overflow adding duration to date")
}
}
impl_add_assign!(Date: Duration, StdDuration);
impl Sub<Duration> for Date {
type Output = Self;
fn sub(self, duration: Duration) -> Self::Output {
self.checked_sub(duration)
.expect("overflow subtracting duration from date")
}
}
impl Sub<StdDuration> for Date {
type Output = Self;
fn sub(self, duration: StdDuration) -> Self::Output {
Self::from_julian_day(
self.to_julian_day() - (duration.as_secs() / Second.per(Day) as u64) as i32,
)
.expect("overflow subtracting duration from date")
}
}
impl_sub_assign!(Date: Duration, StdDuration);
impl Sub for Date {
type Output = Duration;
fn sub(self, other: Self) -> Self::Output {
Duration::days((self.to_julian_day() - other.to_julian_day()) as _)
}
}
// endregion trait impls