Module zone

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 or jiff are available for this purpose. See our example.

Re-exports

pub use iana::IanaParser;

pub use iana::IanaParserBorrowed;

pub use windows::WindowsParser;

pub use windows::WindowsParserBorrowed;

Modules

iana

Tools for parsing IANA time zone IDs.

models

Time zone data model choices.

windows

Tools for parsing Windows timezone IDs.

Structs

InvalidOffsetError

The time zone offset was invalid. Must be within ±18:00:00.

TimeZone

A CLDR time zone identity.

TimeZoneInfo

A utility type that can hold time zone information.

UtcOffset

An offset from Coordinated Universal Time (UTC).

VariantOffsets

Represents the different offsets in use for a time zone

VariantOffsetsCalculator

VariantOffsetsCalculator uses data from the data provider to calculate time zone offsets.

VariantOffsetsCalculatorBorrowed

The borrowed version of a VariantOffsetsCalculator

ZoneNameTimestamp

The moment in time for resolving a time zone name.

Enums

TimeZoneVariant

A time zone variant, such as Standard Time, or Daylight/Summer Time.