mozilla-central/third_party/rust/icu_time/src/zone
Name Description Size
iana.rs Tools for parsing IANA time zone IDs. 22792
mod.rs Types for resolving and manipulating time zones. # Fields In ICU4X, a [`TimeZoneInfo`] consists of up to four different fields: 1. The time zone ID 2. The offset from UTC 3. A timestamp, as time zone names can change over time 4. The zone variant, representing concepts such as Standard, Summer, Daylight, and Ramadan time ## Time Zone The time zone ID corresponds to a time zone from the time zone database. The time zone ID usually corresponds to the largest city in the time zone. There are two mostly-interchangeable standards for time zone IDs: 1. IANA time zone IDs, like `"America/Chicago"` 2. BCP-47 time zone IDs, like `"uschi"` ICU4X uses BCP-47 time zone IDs for all of its APIs. To get a BCP-47 time zone from an IANA time zone, use [`IanaParser`]. ## UTC Offset The UTC offset precisely states the time difference between the time zone in question and Coordinated Universal Time (UTC). In localized strings, it is often rendered as "UTC-6", meaning 6 hours less than UTC (some locales use the term "GMT" instead of "UTC"). ## Timestamp Some time zones change names over time, such as when changing "metazone". For example, Portugal changed from "Western European Time" to "Central European Time" and back in the 1990s, without changing time zone ID (`Europe/Lisbon`, `ptlis`). Therefore, a timestamp is needed to resolve such generic time zone names. It is not required to set the timestamp on [`TimeZoneInfo`]. If it is not set, some string formats may be unsupported. ## Zone Variant Many zones use different names and offsets in the summer than in the winter. In ICU4X, this is called the _zone variant_. CLDR has two zone variants, named `"standard"` and `"daylight"`. However, the mapping of these variants to specific observed offsets varies from time zone to time zone, and they may not consistently represent winter versus summer time. Note: It is not required to set the zone variant on [`TimeZoneInfo`]. If it is not set, some string formats may be unsupported. # Obtaining time zone information This crate does not ship time zone offset information. Other Rust crates such as [`chrono_tz`](https://docs.rs/chrono-tz) or [`jiff`](https://docs.rs/jiff) are available for this purpose. See our [`example`](https://github.com/unicode-org/icu4x/blob/main/components/icu/examples/chrono_jiff.rs). 18042
offset.rs ±hh 11387
windows.rs Tools for parsing Windows timezone IDs. 6145
zone_name_timestamp.rs 15469