Intl & Temporal

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Both namespaces are implemented in pure Zig against checked-in data tables. There is no ICU dependency and no runtime data download: locale data, plural rules, number systems, time-zone rules, and unit data are generated into Zig source and compiled in.

The test/intl402 subtree — including its Temporal areas — is part of the configured test262 corpus, so both namespaces are scored on every run. See Conformance.

`Intl`

Constructor	Purpose
`Intl.Collator`	Locale-aware string comparison.
`Intl.NumberFormat`	Numbers, currencies, units, notation, and `formatToParts`.
`Intl.DateTimeFormat`	Dates and times, including ranges and `formatToParts`.
`Intl.RelativeTimeFormat`	"3 days ago" style formatting.
`Intl.PluralRules`	Cardinal and ordinal plural category selection.
`Intl.ListFormat`	Conjunction / disjunction / unit list joining.
`Intl.DisplayNames`	Names for languages, regions, scripts, currencies, calendars.
`Intl.Segmenter`	Grapheme, word, and sentence segmentation with `containing`.
`Intl.DurationFormat`	Duration formatting.
`Intl.Locale`	Locale identifier parsing, `maximize`/`minimize`, and the `getCalendars` / `getCollations` / `getHourCycles` / `getNumberingSystems` / `getTextInfo` / `getTimeZones` / `getWeekInfo` accessors, plus `firstDayOfWeek`.

Namespace functions: Intl.getCanonicalLocales and Intl.supportedValuesOf.

Every constructor implements the standard resolution pipeline — option coercion, locale negotiation, and resolvedOptions() reporting what was actually selected.

Where the data comes from

Table	Source module
Locale/likely-subtags data	`cldr_locale.zig`
Number formats and symbols	`cldr_numbers.zig`, `numbering_systems.zig`
Plural rules	`cldr_plurals.zig`
Date/time patterns	`cldr_timedata.zig`
Time-zone aliases	`cldr_tzalias.zig`
Zone rules and offsets	`iana_zones.zig`, `iana_offsets.zig`
Display names	`intl_displaynames_data.zig`
Locale info (text direction, week data)	`intl_localeinfo.zig`, `intl_weekdata.zig`
Units	`intl_units_data.zig`
Segmentation	`unicode_grapheme_data.zig`

These are generated by the tools/gen_* scripts (gen_cldr_*.ts, gen_iana_offsets.ts, gen_dn.ts, gen_localeinfo.ts, gen_units.ts, gen_weekdata.ts, gen_numbering.ts, gen_grapheme.ts). TypeScript generators run through ~/Code/Home/lang/zig-out/bin/home-tool. Regenerate the tables from an upstream bump — never hand-edit the .zig tables.

`Temporal`

The Temporal namespace provides:

Temporal.Now
Temporal.Instant
Temporal.Duration
Temporal.PlainDate, Temporal.PlainTime, Temporal.PlainDateTime
Temporal.PlainYearMonth, Temporal.PlainMonthDay
Temporal.ZonedDateTime

Arithmetic, rounding, comparison, calendar and time-zone handling, and the ISO-8601 string round-trips are implemented against the same IANA tables that back Date and Intl.DateTimeFormat, so a zone answer is consistent across all three.

Keeping the data current

A time-zone or CLDR release changes real behaviour. When bumping:

Re-run the relevant tools/gen_* generator against the new upstream release.
Run the full corpus — test/intl402 and test/built-ins/Date are the sensitive subtrees.
Record the flip count in the commit body, as with any conformance change.

See the contributing guide for the generated-file policy.