Registry / serialization / tzdata-backward

tzdata-backward

library1.0.49jsnpmunverified

Part of the IANA time zone database (backward compatibility zones) distributed as JSON for Node.js and browsers. Version 1.0.49 corresponds to tzdata 2026b. This module is part of a split package strategy, requiring peer dependencies for other region modules (tzdata-africa, tzdata-asia, etc.) because the data contains links to zones in those modules. Designed primarily for use with timezonecomplete library, but usable standalone for time zone data consumption. Releases follow IANA tzdata releases. The 'backward' module contains historical zone names that map to canonical zones.

serialization data

npm install tzdata-backward

github ↗package ↗

INSTALL

IMPORT

SIG · TZDATA-BACKWARD

tzdata-backward

serializationjavascriptv1.0.49

Install

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Import

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Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ const tz = require('tzdata-backward');

✗ import tz from 'tzdata-backward';

Package uses CommonJS, not ESM. ESM dynamic import works: import('tzdata-backward')

default (browser UMD)

✓ <script src='tzdata-backward.js'><script>const data = tzdataBackward;

✗ <script src='tzdata-backward.js'><script>const data = require('tzdata-backward');

UMD global is tzdataBackward

default (ESM via bundler)

✓ import tz from 'tzdata-backward'; // may require bundler config

✗ const tz = require('tzdata-backward');

No ESM package.json 'type' field; bundlers often handle CJS->ESM

Load the tzdata-backward JSON in Node.js, examine a zone's existence, and inspect data shape.

const tz = require('tzdata-backward'); console.log('Number of zones:', Object.keys(tz).length); // Example zone data const zone = 'America/Atka'; console.log('Zone ' + zone + ' exists:', zone in tz); // List first 3 zones const names = Object.keys(tz).slice(0,3); console.log('First zones:', names); if (names.length > 0) { const firstZone = tz[names[0]]; console.log('Data shape for ' + names[0] + ':', firstZone); }

Debug

Known issues

gotchaMissing peer dependencies will cause zone links to fail when resolving time zone data.

fix

Install all peer dependencies: tzdata-africa, tzdata-asia, tzdata-australasia, tzdata-etcetera, tzdata-europe, tzdata-northamerica, tzdata-southamerica.

affects: *

breakingWhen upgrading from tzdata 2023c to 2023d, zone 'America/Godthab' was removed (replaced by 'America/Nuuk').

fix

Replace references to 'America/Godthab' with 'America/Nuuk'.

affects: >=1.0.39

deprecatedThe 'backward' module is intended only for backward compatibility; prefer canonical zone names from the primary tzdata modules.

fix

Use zone data from tzdata (main) or region-specific modules (e.g., tzdata-northamerica) instead of relying on backward links.

affects: *

gotchaThe JSON keys are zone names (e.g., 'America/Atka') but some are aliases that redirect to canonical zones. The value is the raw zone data, not a reference resolution.

fix

Manually follow the 'links' if present in the zone object? Actually data does not include resolution; user must handle linking logic externally.

affects: *

breakingtdata 2024a introduced Kazakhstan time zone changes (Asia/Almaty, Asia/Qostanay) affecting backward links.

fix

Update cached zone data and verify calculations for Asia/Almaty and Asia/Qostanay.

affects: >=1.0.40

Errors

Common errors & fixes

Cannot find module 'tzdata-backward'

Package not installed or missing from node_modules

fix

npm install tzdata-backward

Error: Cannot find module 'tzdata-africa' (and similar peer deps)

Peer dependencies not installed automatically by npm

fix

npm install tzdata-africa tzdata-asia tzdata-australasia tzdata-etcetera tzdata-europe tzdata-northamerica tzdata-southamerica

TypeError: require(...) is not a function

Using ES module import syntax on CJS module without proper bundler or node --experimental-require-module

fix

Use 'const tz = require("tzdata-backward")' or use dynamic import with await import('tzdata-backward')

Upgrade

Version history

1.0.49latest on npm

Audit

Dependencies

tzdata-australasiarequiredpeer dependency: contains zones linked from backward data

tzdata-southamericarequiredpeer dependency: contains zones linked from backward data

tzdata-europerequiredpeer dependency: contains zones linked from backward data

tzdata-northamericarequiredpeer dependency: contains zones linked from backward data

tzdata-africarequiredpeer dependency: contains zones linked from backward data

tzdata-etceterarequiredpeer dependency: contains zones linked from backward data

tzdata-asiarequiredpeer dependency: contains zones linked from backward data

Agent activity

18 hits · last 30 days

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OpenAI (training)

Resources

githubhttps://github.com/rogierschouten/tzdata-generate ↗

packagehttps://www.npmjs.com/package/tzdata-backward ↗