# tzinfo

> parse tzinfo files

Latest version **0.5.1** (published 2018-09-16) · Apache-2.0 license · 0 weekly downloads

## Install

```sh
npm install tzinfo
pnpm add tzinfo
yarn add tzinfo
bun add tzinfo
```

## Health

**Score 15/100 (F)** — status: abandoned.

Positive: no vulnerabilities.

Warnings: low downloads; no types; no esm support; pre 1.0.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 0.5.1 |
| Published | 2018-09-16 |
| First published | 2017-11-26 |
| Weekly downloads | 0 |
| License | Apache-2.0 |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 0 |
| Unpacked size | 36 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| Author | Andras |
| Maintainers | andrasq |
| Keywords | tz, tzinfo, tzdata, timezone, parse |

## Links

- npm: https://www.npmjs.com/package/tzinfo
- Repository: https://github.com/andrasq/node-tzinfo
- Homepage: https://github.com/andrasq/node-tzinfo#readme
- Issues: https://github.com/andrasq/node-tzinfo/issues
- npm.io page: https://npm.io/package/tzinfo

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## Recent versions

- 0.5.1 (latest) — 2018-09-16
- 0.4.1 — 2017-11-26

## README

tzinfo
======

[![Build Status](https://api.travis-ci.org/andrasq/node-tzinfo.svg?branch=master)](https://travis-ci.org/andrasq/node-tzinfo?branch=master)
[![Coverage Status](https://codecov.io/github/andrasq/node-tzinfo/coverage.svg?branch=master)](https://codecov.io/github/andrasq/node-tzinfo?branch=master)

Functions to parse /usr/share/zoneinfo timezone info files.
Parses both v1 and v2 format zoneinfo files.


Api
---

### tzinfo.getZoneinfoDirectory( )

Return the auto-detected directory containing the system zoneinfo files.

### tzinfo.listZoneinfoFiles( zoneinfoDirectory )

List all the zoneinfo files contained in the named zoneinfo directory.  Recursively
walks the directory and tests each file found.  This is a blocking operation, so call
only on program load.  The results are small and can be easily cached.

### tzinfo.readZoneinfoFile( tzname, cb )

Read the zoneinfo file corresponding to the named timezone.  Returns to its callback a
`Buffer` with the file contents, or an `Error`.

### tzinfo.readZoneinfoFileSync( tzname )

Read the zoneinfo file corresponding to the named timezone.  Returns a `Buffer`
containing the file contents, or throws an `Error`.

### tzinfo.parseZoneinfo( buf )

Parse the zoneinfo file contained in `buf` and return it as an object.

Returned object format:

    zoneinfo = {
        magic:      // 'TZif'
        version:    // '\0' or '2'

        ttisgmtcnt: // num gmt/local indicators stored in `ttisgmt`
        ttisstdcnt: // num standard/wall indicators stored in `ttisstd`
        leapcnt:    // num leap seconds for which data is stored in `leaps`
        timecnt:    // num transition types stored in `types`
        typecnt:    // num time transition structs stored in `tzinfo`
        charcnt:    // total num chars to store the tz name abbreviations

        ttimes:     // array of `timecnt` transition time timestamps
        types:      // array of `timecnt` tzinfo indices for each time transitioned to
        tzinfo:     // array of `typecnt` tzinfo structs
                    //     { idx: , tt_gmtoff: , tt_isdst: , tt_abbrind: }
        abbrevs:    // concatenated tz name abbreviations (asciiz strings totaling charcnt bytes)
        leaps:      // array of `leapcnt` leap second descriptors
        ttisstd:    // array of `ttisstdcnt` transitions of tzinfo were std or wallclock times
        ttisgmt:    // array of `ttisgmtcnt` transitions of tzinfo were UTC or local time
    };

### tzinfo.findTzinfo( zoneinfo, date [,firstIfTooOld] )

Find in the parsed `zoneinfo` the index of the tzinfo struct corresponding to the
given `date`.  Returns a `tzinfo` struct or `false` if the date is before the earliest
time transition on record or if date is not valid.  If `date` precedes the first known
time transition but `firstIfTooOld` is truthy, it returns the oldest tzinfo struct.
If there are no time transitions defined but there is a tzinfo struct, it returns the
tzinfo struct (to always succeed for GMT and UTC).

Tzinfo format:

    tzinfo = {
        idx:        // index of this entry in `zoneinfo.tzinfo`
        tt_gmtoff:  // seconds to add to GMT to get localtime
        tt_isdst:   // whether daylight saving is in effect
        tt_abbrind: // byte offset in abbrevs of tz name abbreviation
        abbrev:     // timezone name abbreviation, eg 'EDT'
    };

To find the POSIX-style timezone environment variable attributes associated with this `tzinfo`,
look at `zoneinfo.ttisstd[tzinfo.idx]` and `zoneinfo.ttisgmt[tzinfo.idx]`.


Change Log
----------

- 0.5.1 - always find GMT zoneinfo
- 0.5.0 - findTzinfo option to return the oldest known tzinfo struct for very old dates
- 0.4.2 - more tests, make `readStringZ` stop on unterminated strings
- 0.4.1 - npm tag
- 0.4.0 - `listZoneinfoFiles()`, `getZoneinfoDirectory()`
- 0.3.0 - `readZoneinfoFile` and `readZoneinfoFileSync`, `findTzinfo`
- 0.2.0 - first published release, with `parseZoneinfo`


Todo
----

- `setZoneinfoDirectory` to override the auto-detected one


Related Work
------------

- [zoneinfo](http://npmjs.com/package/zoneinfo)
- `tzfile(5)`, `zdump(8)`, `zic(8)` - unix zoneinfo manpages

---
_Source: https://npm.io/package/tzinfo · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._