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::{MappedLocalTime, 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] east(secs: i32) -> FixedOffset41 pub fn east(secs: i32) -> FixedOffset { 42 FixedOffset::east_opt(secs).expect("FixedOffset::east out of bounds") 43 } 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 /// ``` 53 /// # #[cfg(feature = "alloc")] { 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 /// ``` 61 #[must_use] east_opt(secs: i32) -> Option<FixedOffset>62 pub const fn east_opt(secs: i32) -> Option<FixedOffset> { 63 if -86_400 < secs && secs < 86_400 { 64 Some(FixedOffset { local_minus_utc: secs }) 65 } else { 66 None 67 } 68 } 69 70 /// Makes a new `FixedOffset` for the Western Hemisphere with given timezone difference. 71 /// The negative `secs` means the Eastern Hemisphere. 72 /// 73 /// Panics on the out-of-bound `secs`. 74 #[deprecated(since = "0.4.23", note = "use `west_opt()` instead")] 75 #[must_use] west(secs: i32) -> FixedOffset76 pub fn west(secs: i32) -> FixedOffset { 77 FixedOffset::west_opt(secs).expect("FixedOffset::west out of bounds") 78 } 79 80 /// Makes a new `FixedOffset` for the Western Hemisphere with given timezone difference. 81 /// The negative `secs` means the Eastern Hemisphere. 82 /// 83 /// Returns `None` on the out-of-bound `secs`. 84 /// 85 /// # Example 86 /// 87 /// ``` 88 /// # #[cfg(feature = "alloc")] { 89 /// use chrono::{FixedOffset, TimeZone}; 90 /// let hour = 3600; 91 /// let datetime = 92 /// FixedOffset::west_opt(5 * hour).unwrap().with_ymd_and_hms(2016, 11, 08, 0, 0, 0).unwrap(); 93 /// assert_eq!(&datetime.to_rfc3339(), "2016-11-08T00:00:00-05:00") 94 /// # } 95 /// ``` 96 #[must_use] west_opt(secs: i32) -> Option<FixedOffset>97 pub const fn west_opt(secs: i32) -> Option<FixedOffset> { 98 if -86_400 < secs && secs < 86_400 { 99 Some(FixedOffset { local_minus_utc: -secs }) 100 } else { 101 None 102 } 103 } 104 105 /// Returns the number of seconds to add to convert from UTC to the local time. 106 #[inline] local_minus_utc(&self) -> i32107 pub const fn local_minus_utc(&self) -> i32 { 108 self.local_minus_utc 109 } 110 111 /// Returns the number of seconds to add to convert from the local time to UTC. 112 #[inline] utc_minus_local(&self) -> i32113 pub const fn utc_minus_local(&self) -> i32 { 114 -self.local_minus_utc 115 } 116 } 117 118 /// Parsing a `str` into a `FixedOffset` uses the format [`%z`](crate::format::strftime). 119 impl FromStr for FixedOffset { 120 type Err = ParseError; from_str(s: &str) -> Result<Self, Self::Err>121 fn from_str(s: &str) -> Result<Self, Self::Err> { 122 let (_, offset) = scan::timezone_offset(s, scan::colon_or_space, false, false, true)?; 123 Self::east_opt(offset).ok_or(OUT_OF_RANGE) 124 } 125 } 126 127 impl TimeZone for FixedOffset { 128 type Offset = FixedOffset; 129 from_offset(offset: &FixedOffset) -> FixedOffset130 fn from_offset(offset: &FixedOffset) -> FixedOffset { 131 *offset 132 } 133 offset_from_local_date(&self, _local: &NaiveDate) -> MappedLocalTime<FixedOffset>134 fn offset_from_local_date(&self, _local: &NaiveDate) -> MappedLocalTime<FixedOffset> { 135 MappedLocalTime::Single(*self) 136 } offset_from_local_datetime(&self, _local: &NaiveDateTime) -> MappedLocalTime<FixedOffset>137 fn offset_from_local_datetime(&self, _local: &NaiveDateTime) -> MappedLocalTime<FixedOffset> { 138 MappedLocalTime::Single(*self) 139 } 140 offset_from_utc_date(&self, _utc: &NaiveDate) -> FixedOffset141 fn offset_from_utc_date(&self, _utc: &NaiveDate) -> FixedOffset { 142 *self 143 } offset_from_utc_datetime(&self, _utc: &NaiveDateTime) -> FixedOffset144 fn offset_from_utc_datetime(&self, _utc: &NaiveDateTime) -> FixedOffset { 145 *self 146 } 147 } 148 149 impl Offset for FixedOffset { fix(&self) -> FixedOffset150 fn fix(&self) -> FixedOffset { 151 *self 152 } 153 } 154 155 impl fmt::Debug for FixedOffset { fmt(&self, f: &mut fmt::Formatter) -> fmt::Result156 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { 157 let offset = self.local_minus_utc; 158 let (sign, offset) = if offset < 0 { ('-', -offset) } else { ('+', offset) }; 159 let sec = offset.rem_euclid(60); 160 let mins = offset.div_euclid(60); 161 let min = mins.rem_euclid(60); 162 let hour = mins.div_euclid(60); 163 if sec == 0 { 164 write!(f, "{}{:02}:{:02}", sign, hour, min) 165 } else { 166 write!(f, "{}{:02}:{:02}:{:02}", sign, hour, min, sec) 167 } 168 } 169 } 170 171 impl fmt::Display for FixedOffset { fmt(&self, f: &mut fmt::Formatter) -> fmt::Result172 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { 173 fmt::Debug::fmt(self, f) 174 } 175 } 176 177 #[cfg(all(feature = "arbitrary", feature = "std"))] 178 impl arbitrary::Arbitrary<'_> for FixedOffset { arbitrary(u: &mut arbitrary::Unstructured) -> arbitrary::Result<FixedOffset>179 fn arbitrary(u: &mut arbitrary::Unstructured) -> arbitrary::Result<FixedOffset> { 180 let secs = u.int_in_range(-86_399..=86_399)?; 181 let fixed_offset = FixedOffset::east_opt(secs) 182 .expect("Could not generate a valid chrono::FixedOffset. It looks like implementation of Arbitrary for FixedOffset is erroneous."); 183 Ok(fixed_offset) 184 } 185 } 186 187 #[cfg(test)] 188 mod tests { 189 use super::FixedOffset; 190 use crate::offset::TimeZone; 191 use std::str::FromStr; 192 193 #[test] test_date_extreme_offset()194 fn test_date_extreme_offset() { 195 // starting from 0.3 we don't have an offset exceeding one day. 196 // this makes everything easier! 197 let offset = FixedOffset::east_opt(86399).unwrap(); 198 assert_eq!( 199 format!("{:?}", offset.with_ymd_and_hms(2012, 2, 29, 5, 6, 7).unwrap()), 200 "2012-02-29T05:06:07+23:59:59" 201 ); 202 let offset = FixedOffset::east_opt(-86399).unwrap(); 203 assert_eq!( 204 format!("{:?}", offset.with_ymd_and_hms(2012, 2, 29, 5, 6, 7).unwrap()), 205 "2012-02-29T05:06:07-23:59:59" 206 ); 207 let offset = FixedOffset::west_opt(86399).unwrap(); 208 assert_eq!( 209 format!("{:?}", offset.with_ymd_and_hms(2012, 3, 4, 5, 6, 7).unwrap()), 210 "2012-03-04T05:06:07-23:59:59" 211 ); 212 let offset = FixedOffset::west_opt(-86399).unwrap(); 213 assert_eq!( 214 format!("{:?}", offset.with_ymd_and_hms(2012, 3, 4, 5, 6, 7).unwrap()), 215 "2012-03-04T05:06:07+23:59:59" 216 ); 217 } 218 219 #[test] test_parse_offset()220 fn test_parse_offset() { 221 let offset = FixedOffset::from_str("-0500").unwrap(); 222 assert_eq!(offset.local_minus_utc, -5 * 3600); 223 let offset = FixedOffset::from_str("-08:00").unwrap(); 224 assert_eq!(offset.local_minus_utc, -8 * 3600); 225 let offset = FixedOffset::from_str("+06:30").unwrap(); 226 assert_eq!(offset.local_minus_utc, (6 * 3600) + 1800); 227 } 228 229 #[test] 230 #[cfg(feature = "rkyv-validation")] test_rkyv_validation()231 fn test_rkyv_validation() { 232 let offset = FixedOffset::from_str("-0500").unwrap(); 233 let bytes = rkyv::to_bytes::<_, 4>(&offset).unwrap(); 234 assert_eq!(rkyv::from_bytes::<FixedOffset>(&bytes).unwrap(), offset); 235 } 236 } 237