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    timezones-ical-library
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    1.5.0 • Public • Published

    Add to Calendar TimeZone iCal Library

    Codacy Grade GitHub Workflow Status npm Installations GitHub license


    Add to Calendar TimeZones iCal Library

    The tool to convert the IANA (formerly Olson) time zone database files into VTIMEZONE blocks, compatible with the iCalendar specification (RFC2445).

    It is based on the awesome tool by Damon Chaplin (github.com/libical/vzic), but only provides the VTIMEZONE part to easily put this into any other iCal generator (like the add-to-calendar-button). It is built to be used standalone or as JavaScript module, hosted as npm package.





    📦 Installation / Setup

    0. Update it (not required)

    This step is only relevant if you want to build the package and data on your own and from source! (Requires Node.js as well as Linux as operating system.) Run ...

    sudo sh update-tzdata.sh tzVersionNumber
    

    ... with tzVersionNumber being the version of the IANA time zone database you want to use (e.g. sudo sh update-tzdata.sh 2022e).


    1. Load it

    Install the package via npm with:

    npm install timezones-ical-library
    

    After the installation:

    • require the package (commonJS) or ...
    • import the module (ES) via import { tzlib_get_ical_block, tzlib_get_offset, tzlib_get_timezones } from 'timezones-ical-library';.

    2. Use it

    A. Get time zones

    Use tzlib_get_timezones() to retrieve a list of all available time zone strings. You can pass true to retrieve a JSON formatted string instead of an array.

    B. Get the iCal time zone block

    Use the tzlib_get_ical_block(tzName) function to return the proper iCal VTIMEZONE block for a given time zone string (tzName). Again, pass true to retrieve a JSON formatted string instead of an array (not recommended).

    You will receive an array, holding the VTIMEZONE block first, and the TZID line (additionally) second. The latter one is needed for any further time statement.

    Include this into your further iCal data to come up with a complete ics file.

    A final constellation could look like this:

    BEGIN:VCALENDAR
    VERSION:2.0
    PRODID:-// github.com/add2cal/add-to-calendar-button //EN
    CALSCALE:GREGORIAN
    
    BEGIN:VTIMEZONE
    TZID:America/New_York
    LAST-MODIFIED:20220824T133813Z
    X-LIC-LOCATION:America/New_York
    BEGIN:DAYLIGHT
    TZNAME:EDT
    TZOFFSETFROM:-0500
    TZOFFSETTO:-0400
    DTSTART:19700308T020000
    RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
    END:DAYLIGHT
    BEGIN:STANDARD
    TZNAME:EST
    TZOFFSETFROM:-0400
    TZOFFSETTO:-0500
    DTSTART:19701101T020000
    RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
    END:STANDARD
    END:VTIMEZONE
    
    BEGIN:VEVENT
    UID:2022-08-30T19:29:38.618Z@add-to-calendar-button
    DTSTAMP:20230214T091500Z
    DTSTART;TZID=America/New_York:20230214T091500
    DTEND;TZID=America/New_York:20230218T223000
    SUMMARY:A sample event
    DESCRIPTION:Just some descriptive text...
    LOCATION:World Wide Web
    STATUS:CONFIRMED
    LAST-MODIFIED:20220830T192938Z
    SEQUENCE:0
    END:VEVENT
    END:VCALENDAR
    

    C. Get a specific offset

    Use tzlib_get_offset(tzName, isoDate, isoTime) to get specific offset (relative to UTC), based on a provided date and time.

    For example, you can provide tzName 'Europe/Berlin', isoDate '2023-05-23', and isoTime '15:45' in order to retrieve the offset, which applies for this time zone at the 23rd of May in 2023 at exactly 15:45.





    ⚙️ API

    Instead of using this code or the npm package, you could also make use of the free and open API.

    Getting a list of all zone names

    https://tz.add-to-calendar-technology.com/api/zones.json
    

    Getting the ics part of a respective zone

    https://tz.add-to-calendar-technology.com/api/%zoneName%.ics
    

    With %zoneName% being your time zone. So, for New York, this would be https://tz.add-to-calendar-technology.com/api/America/New_York.ics. This is case sensitive!

    (Mind that this does not deliver a fully valid ics file, since it only contains the VTIMEZONE part. You will need to combine this with your other event information.)





    🙌 Contributing

    Anyone is welcome to contribute, but mind the guidelines:


    📃 Copyright and License

    Copyright (c) Jens Kuerschner.

    Licensed under Apache-2.0.


    Changelog (without minor changes and fixes)

    • v1.5 : new dist structure
    • v1.4 : further minification via data mapping
    • v1.3 : bundle size optimization and API
    • v1.2 : providing tzblock as array with separate tzid
    • v1.1 : get-offset function
    • v1.0 : initial release


    💜 Kudos go to

    Install

    npm i timezones-ical-library

    DownloadsWeekly Downloads

    4,393

    Version

    1.5.0

    License

    Apache-2.0

    Unpacked Size

    130 kB

    Total Files

    13

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    Collaborators

    • jekuer
    • add-to-calendar