/rust/registry/src/index.crates.io-1949cf8c6b5b557f/chrono-0.4.35/src/offset/fixed.rs

Source
// This is a part of Chrono.
// See README.md and LICENSE.txt for details.

//! The time zone which has a fixed offset from UTC.

use core::fmt;
use core::str::FromStr;

#[cfg(any(feature = "rkyv", feature = "rkyv-16", feature = "rkyv-32", feature = "rkyv-64"))]
use rkyv::{Archive, Deserialize, Serialize};

use super::{LocalResult, Offset, TimeZone};
use crate::format::{scan, ParseError, OUT_OF_RANGE};
use crate::naive::{NaiveDate, NaiveDateTime};

/// The time zone with fixed offset, from UTC-23:59:59 to UTC+23:59:59.
///
/// Using the [`TimeZone`](./trait.TimeZone.html) methods
/// on a `FixedOffset` struct is the preferred way to construct
/// `DateTime<FixedOffset>` instances. See the [`east_opt`](#method.east_opt) and
/// [`west_opt`](#method.west_opt) methods for examples.
#[derive(PartialEq, Eq, Hash, Copy, Clone)]
#[cfg_attr(
    any(feature = "rkyv", feature = "rkyv-16", feature = "rkyv-32", feature = "rkyv-64"),
    derive(Archive, Deserialize, Serialize),
    archive(compare(PartialEq)),
    archive_attr(derive(Clone, Copy, PartialEq, Eq, Hash, Debug))
)]
#[cfg_attr(feature = "rkyv-validation", archive(check_bytes))]
pub struct FixedOffset {
    local_minus_utc: i32,
}

impl FixedOffset {
    /// Makes a new `FixedOffset` for the Eastern Hemisphere with given timezone difference.
    /// The negative `secs` means the Western Hemisphere.
    ///
    /// Panics on the out-of-bound `secs`.
    #[deprecated(since = "0.4.23", note = "use `east_opt()` instead")]
    #[must_use]
    pub fn east(secs: i32) -> FixedOffset {
        FixedOffset::east_opt(secs).expect("FixedOffset::east out of bounds")
    }

    /// Makes a new `FixedOffset` for the Eastern Hemisphere with given timezone difference.
    /// The negative `secs` means the Western Hemisphere.
    ///
    /// Returns `None` on the out-of-bound `secs`.
    ///
    /// # Example
    ///
    #[cfg_attr(not(feature = "std"), doc = "```ignore")]
    #[cfg_attr(feature = "std", doc = "```")]
    /// use chrono::{FixedOffset, TimeZone};
    /// let hour = 3600;
    /// let datetime =
    ///     FixedOffset::east_opt(5 * hour).unwrap().with_ymd_and_hms(2016, 11, 08, 0, 0, 0).unwrap();
    /// assert_eq!(&datetime.to_rfc3339(), "2016-11-08T00:00:00+05:00")
    /// ```
    #[must_use]
    pub const fn east_opt(secs: i32) -> Option<FixedOffset> {
        if -86_400 < secs && secs < 86_400 {
            Some(FixedOffset { local_minus_utc: secs })
        } else {
            None
        }
    }

    /// Makes a new `FixedOffset` for the Western Hemisphere with given timezone difference.
    /// The negative `secs` means the Eastern Hemisphere.
    ///
    /// Panics on the out-of-bound `secs`.
    #[deprecated(since = "0.4.23", note = "use `west_opt()` instead")]
    #[must_use]
    pub fn west(secs: i32) -> FixedOffset {
        FixedOffset::west_opt(secs).expect("FixedOffset::west out of bounds")
    }

    /// Makes a new `FixedOffset` for the Western Hemisphere with given timezone difference.
    /// The negative `secs` means the Eastern Hemisphere.
    ///
    /// Returns `None` on the out-of-bound `secs`.
    ///
    /// # Example
    ///
    #[cfg_attr(not(feature = "std"), doc = "```ignore")]
    #[cfg_attr(feature = "std", doc = "```")]
    /// use chrono::{FixedOffset, TimeZone};
    /// let hour = 3600;
    /// let datetime =
    ///     FixedOffset::west_opt(5 * hour).unwrap().with_ymd_and_hms(2016, 11, 08, 0, 0, 0).unwrap();
    /// assert_eq!(&datetime.to_rfc3339(), "2016-11-08T00:00:00-05:00")
    /// ```
    #[must_use]
    pub const fn west_opt(secs: i32) -> Option<FixedOffset> {
        if -86_400 < secs && secs < 86_400 {
            Some(FixedOffset { local_minus_utc: -secs })
        } else {
            None
        }
    }

    /// Returns the number of seconds to add to convert from UTC to the local time.
    #[inline]
    pub const fn local_minus_utc(&self) -> i32 {
        self.local_minus_utc
    }

    /// Returns the number of seconds to add to convert from the local time to UTC.
    #[inline]
    pub const fn utc_minus_local(&self) -> i32 {
        -self.local_minus_utc
    }
}

/// Parsing a `str` into a `FixedOffset` uses the format [`%z`](crate::format::strftime).
impl FromStr for FixedOffset {
    type Err = ParseError;
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let (_, offset) = scan::timezone_offset(s, scan::colon_or_space, false, false, true)?;
        Self::east_opt(offset).ok_or(OUT_OF_RANGE)
    }
}

impl TimeZone for FixedOffset {
    type Offset = FixedOffset;

    fn from_offset(offset: &FixedOffset) -> FixedOffset {
        *offset
    }

    fn offset_from_local_date(&self, _local: &NaiveDate) -> LocalResult<FixedOffset> {
        LocalResult::Single(*self)
    }
    fn offset_from_local_datetime(&self, _local: &NaiveDateTime) -> LocalResult<FixedOffset> {
        LocalResult::Single(*self)
    }

    fn offset_from_utc_date(&self, _utc: &NaiveDate) -> FixedOffset {
        *self
    }
    fn offset_from_utc_datetime(&self, _utc: &NaiveDateTime) -> FixedOffset {
        *self
    }
}

impl Offset for FixedOffset {
    fn fix(&self) -> FixedOffset {
        *self
    }
}

impl fmt::Debug for FixedOffset {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        let offset = self.local_minus_utc;
        let (sign, offset) = if offset < 0 { ('-', -offset) } else { ('+', offset) };
        let sec = offset.rem_euclid(60);
        let mins = offset.div_euclid(60);
        let min = mins.rem_euclid(60);
        let hour = mins.div_euclid(60);
        if sec == 0 {
            write!(f, "{}{:02}:{:02}", sign, hour, min)
        } else {
            write!(f, "{}{:02}:{:02}:{:02}", sign, hour, min, sec)
        }
    }
}

impl fmt::Display for FixedOffset {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        fmt::Debug::fmt(self, f)
    }
}

#[cfg(all(feature = "arbitrary", feature = "std"))]
impl arbitrary::Arbitrary<'_> for FixedOffset {
    fn arbitrary(u: &mut arbitrary::Unstructured) -> arbitrary::Result<FixedOffset> {
        let secs = u.int_in_range(-86_399..=86_399)?;
        let fixed_offset = FixedOffset::east_opt(secs)
            .expect("Could not generate a valid chrono::FixedOffset. It looks like implementation of Arbitrary for FixedOffset is erroneous.");
        Ok(fixed_offset)
    }
}

#[cfg(test)]
mod tests {
    use super::FixedOffset;
    use crate::offset::TimeZone;
    use std::str::FromStr;

    #[test]
    fn test_date_extreme_offset() {
        // starting from 0.3 we don't have an offset exceeding one day.
        // this makes everything easier!
        let offset = FixedOffset::east_opt(86399).unwrap();
        assert_eq!(
            format!("{:?}", offset.with_ymd_and_hms(2012, 2, 29, 5, 6, 7).unwrap()),
            "2012-02-29T05:06:07+23:59:59"
        );
        let offset = FixedOffset::east_opt(-86399).unwrap();
        assert_eq!(
            format!("{:?}", offset.with_ymd_and_hms(2012, 2, 29, 5, 6, 7).unwrap()),
            "2012-02-29T05:06:07-23:59:59"
        );
        let offset = FixedOffset::west_opt(86399).unwrap();
        assert_eq!(
            format!("{:?}", offset.with_ymd_and_hms(2012, 3, 4, 5, 6, 7).unwrap()),
            "2012-03-04T05:06:07-23:59:59"
        );
        let offset = FixedOffset::west_opt(-86399).unwrap();
        assert_eq!(
            format!("{:?}", offset.with_ymd_and_hms(2012, 3, 4, 5, 6, 7).unwrap()),
            "2012-03-04T05:06:07+23:59:59"
        );
    }

    #[test]
    fn test_parse_offset() {
        let offset = FixedOffset::from_str("-0500").unwrap();
        assert_eq!(offset.local_minus_utc, -5 * 3600);
        let offset = FixedOffset::from_str("-08:00").unwrap();
        assert_eq!(offset.local_minus_utc, -8 * 3600);
        let offset = FixedOffset::from_str("+06:30").unwrap();
        assert_eq!(offset.local_minus_utc, (6 * 3600) + 1800);
    }

    #[test]
    #[cfg(feature = "rkyv-validation")]
    fn test_rkyv_validation() {
        let offset = FixedOffset::from_str("-0500").unwrap();
        let bytes = rkyv::to_bytes::<_, 4>(&offset).unwrap();
        assert_eq!(rkyv::from_bytes::<FixedOffset>(&bytes).unwrap(), offset);
    }
}

Coverage Report

Created: 2026-03-31 06:24

Line	Count	Source
1		// This is a part of Chrono.
2		// See README.md and LICENSE.txt for details.
3
4		//! The time zone which has a fixed offset from UTC.
5
6		use core::fmt;
7		use core::str::FromStr;
8
9		#[cfg(any(feature = "rkyv", feature = "rkyv-16", feature = "rkyv-32", feature = "rkyv-64"))]
10		use rkyv::{Archive, Deserialize, Serialize};
11
12		use super::{LocalResult, Offset, TimeZone};
13		use crate::format::{scan, ParseError, OUT_OF_RANGE};
14		use crate::naive::{NaiveDate, NaiveDateTime};
15
16		/// The time zone with fixed offset, from UTC-23:59:59 to UTC+23:59:59.
17		///
18		/// Using the [`TimeZone`](./trait.TimeZone.html) methods
19		/// on a `FixedOffset` struct is the preferred way to construct
20		/// `DateTime<FixedOffset>` instances. See the [`east_opt`](#method.east_opt) and
21		/// [`west_opt`](#method.west_opt) methods for examples.
22		#[derive(PartialEq, Eq, Hash, Copy, Clone)]
23		#[cfg_attr(
24		any(feature = "rkyv", feature = "rkyv-16", feature = "rkyv-32", feature = "rkyv-64"),
25		derive(Archive, Deserialize, Serialize),
26		archive(compare(PartialEq)),
27		archive_attr(derive(Clone, Copy, PartialEq, Eq, Hash, Debug))
28		)]
29		#[cfg_attr(feature = "rkyv-validation", archive(check_bytes))]
30		pub struct FixedOffset {
31		local_minus_utc: i32,
32		}
33
34		impl FixedOffset {
35		/// Makes a new `FixedOffset` for the Eastern Hemisphere with given timezone difference.
36		/// The negative `secs` means the Western Hemisphere.
37		///
38		/// Panics on the out-of-bound `secs`.
39		#[deprecated(since = "0.4.23", note = "use `east_opt()` instead")]
40		#[must_use]
41	0	pub fn east(secs: i32) -> FixedOffset {
42	0	FixedOffset::east_opt(secs).expect("FixedOffset::east out of bounds")
43	0	}
44
45		/// Makes a new `FixedOffset` for the Eastern Hemisphere with given timezone difference.
46		/// The negative `secs` means the Western Hemisphere.
47		///
48		/// Returns `None` on the out-of-bound `secs`.
49		///
50		/// # Example
51		///
52		#[cfg_attr(not(feature = "std"), doc = "```ignore")]
53		#[cfg_attr(feature = "std", doc = "```")]
54		/// use chrono::{FixedOffset, TimeZone};
55		/// let hour = 3600;
56		/// let datetime =
57		/// FixedOffset::east_opt(5 * hour).unwrap().with_ymd_and_hms(2016, 11, 08, 0, 0, 0).unwrap();
58		/// assert_eq!(&datetime.to_rfc3339(), "2016-11-08T00:00:00+05:00")
59		/// ```
60		#[must_use]
61	0	pub const fn east_opt(secs: i32) -> Option<FixedOffset> {
62	0	if -86_400 < secs && secs < 86_400 {
63	0	Some(FixedOffset { local_minus_utc: secs })
64		} else {
65	0	None
66		}
67	0	}
68
69		/// Makes a new `FixedOffset` for the Western Hemisphere with given timezone difference.
70		/// The negative `secs` means the Eastern Hemisphere.
71		///
72		/// Panics on the out-of-bound `secs`.
73		#[deprecated(since = "0.4.23", note = "use `west_opt()` instead")]
74		#[must_use]
75	0	pub fn west(secs: i32) -> FixedOffset {
76	0	FixedOffset::west_opt(secs).expect("FixedOffset::west out of bounds")
77	0	}
78
79		/// Makes a new `FixedOffset` for the Western Hemisphere with given timezone difference.
80		/// The negative `secs` means the Eastern Hemisphere.
81		///
82		/// Returns `None` on the out-of-bound `secs`.
83		///
84		/// # Example
85		///
86		#[cfg_attr(not(feature = "std"), doc = "```ignore")]
87		#[cfg_attr(feature = "std", doc = "```")]
88		/// use chrono::{FixedOffset, TimeZone};
89		/// let hour = 3600;
90		/// let datetime =
91		/// FixedOffset::west_opt(5 * hour).unwrap().with_ymd_and_hms(2016, 11, 08, 0, 0, 0).unwrap();
92		/// assert_eq!(&datetime.to_rfc3339(), "2016-11-08T00:00:00-05:00")
93		/// ```
94		#[must_use]
95	0	pub const fn west_opt(secs: i32) -> Option<FixedOffset> {
96	0	if -86_400 < secs && secs < 86_400 {
97	0	Some(FixedOffset { local_minus_utc: -secs })
98		} else {
99	0	None
100		}
101	0	}
102
103		/// Returns the number of seconds to add to convert from UTC to the local time.
104		#[inline]
105	0	pub const fn local_minus_utc(&self) -> i32 {
106	0	self.local_minus_utc
107	0	}
108
109		/// Returns the number of seconds to add to convert from the local time to UTC.
110		#[inline]
111	0	pub const fn utc_minus_local(&self) -> i32 {
112	0	-self.local_minus_utc
113	0	}
114		}
115
116		/// Parsing a `str` into a `FixedOffset` uses the format [`%z`](crate::format::strftime).
117		impl FromStr for FixedOffset {
118		type Err = ParseError;
119	0	fn from_str(s: &str) -> Result<Self, Self::Err> {
120	0	let (_, offset) = scan::timezone_offset(s, scan::colon_or_space, false, false, true)?;
121	0	Self::east_opt(offset).ok_or(OUT_OF_RANGE)
122	0	}
123		}
124
125		impl TimeZone for FixedOffset {
126		type Offset = FixedOffset;
127
128	0	fn from_offset(offset: &FixedOffset) -> FixedOffset {
129	0	*offset
130	0	}
131
132	0	fn offset_from_local_date(&self, _local: &NaiveDate) -> LocalResult<FixedOffset> {
133	0	LocalResult::Single(*self)
134	0	}
135	0	fn offset_from_local_datetime(&self, _local: &NaiveDateTime) -> LocalResult<FixedOffset> {
136	0	LocalResult::Single(*self)
137	0	}
138
139	0	fn offset_from_utc_date(&self, _utc: &NaiveDate) -> FixedOffset {
140	0	*self
141	0	}
142	0	fn offset_from_utc_datetime(&self, _utc: &NaiveDateTime) -> FixedOffset {
143	0	*self
144	0	}
145		}
146
147		impl Offset for FixedOffset {
148	0	fn fix(&self) -> FixedOffset {
149	0	*self
150	0	}
151		}
152
153		impl fmt::Debug for FixedOffset {
154	0	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
155	0	let offset = self.local_minus_utc;
156	0	let (sign, offset) = if offset < 0 { ('-', -offset) } else { ('+', offset) };
157	0	let sec = offset.rem_euclid(60);
158	0	let mins = offset.div_euclid(60);
159	0	let min = mins.rem_euclid(60);
160	0	let hour = mins.div_euclid(60);
161	0	if sec == 0 {
162	0	write!(f, "{}{:02}:{:02}", sign, hour, min)
163		} else {
164	0	write!(f, "{}{:02}:{:02}:{:02}", sign, hour, min, sec)
165		}
166	0	}
167		}
168
169		impl fmt::Display for FixedOffset {
170	0	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
171	0	fmt::Debug::fmt(self, f)
172	0	}
173		}
174
175		#[cfg(all(feature = "arbitrary", feature = "std"))]
176		impl arbitrary::Arbitrary<'_> for FixedOffset {
177		fn arbitrary(u: &mut arbitrary::Unstructured) -> arbitrary::Result<FixedOffset> {
178		let secs = u.int_in_range(-86_399..=86_399)?;
179		let fixed_offset = FixedOffset::east_opt(secs)
180		.expect("Could not generate a valid chrono::FixedOffset. It looks like implementation of Arbitrary for FixedOffset is erroneous.");
181		Ok(fixed_offset)
182		}
183		}
184
185		#[cfg(test)]
186		mod tests {
187		use super::FixedOffset;
188		use crate::offset::TimeZone;
189		use std::str::FromStr;
190
191		#[test]
192		fn test_date_extreme_offset() {
193		// starting from 0.3 we don't have an offset exceeding one day.
194		// this makes everything easier!
195		let offset = FixedOffset::east_opt(86399).unwrap();
196		assert_eq!(
197		format!("{:?}", offset.with_ymd_and_hms(2012, 2, 29, 5, 6, 7).unwrap()),
198		"2012-02-29T05:06:07+23:59:59"
199		);
200		let offset = FixedOffset::east_opt(-86399).unwrap();
201		assert_eq!(
202		format!("{:?}", offset.with_ymd_and_hms(2012, 2, 29, 5, 6, 7).unwrap()),
203		"2012-02-29T05:06:07-23:59:59"
204		);
205		let offset = FixedOffset::west_opt(86399).unwrap();
206		assert_eq!(
207		format!("{:?}", offset.with_ymd_and_hms(2012, 3, 4, 5, 6, 7).unwrap()),
208		"2012-03-04T05:06:07-23:59:59"
209		);
210		let offset = FixedOffset::west_opt(-86399).unwrap();
211		assert_eq!(
212		format!("{:?}", offset.with_ymd_and_hms(2012, 3, 4, 5, 6, 7).unwrap()),
213		"2012-03-04T05:06:07+23:59:59"
214		);
215		}
216
217		#[test]
218		fn test_parse_offset() {
219		let offset = FixedOffset::from_str("-0500").unwrap();
220		assert_eq!(offset.local_minus_utc, -5 * 3600);
221		let offset = FixedOffset::from_str("-08:00").unwrap();
222		assert_eq!(offset.local_minus_utc, -8 * 3600);
223		let offset = FixedOffset::from_str("+06:30").unwrap();
224		assert_eq!(offset.local_minus_utc, (6 * 3600) + 1800);
225		}
226
227		#[test]
228		#[cfg(feature = "rkyv-validation")]
229		fn test_rkyv_validation() {
230		let offset = FixedOffset::from_str("-0500").unwrap();
231		let bytes = rkyv::to_bytes::<_, 4>(&offset).unwrap();
232		assert_eq!(rkyv::from_bytes::<FixedOffset>(&bytes).unwrap(), offset);
233		}
234		}