# kewisch/ical.js

Javascript parser for ics (rfc5545) and vcard (rfc6350) data

Repository: https://github.com/kewisch/ical.js
Canonical: https://ross.abutalabs.com/products/icaljs
Homepage: https://kewisch.github.io/ical.js/
Language: JavaScript
License: MPL-2.0
License Family: copyleft
Topics: ical, icalendar, jcal, jcard
Last push: 2026-08-11T13:34:28+00:00

## Health v2 (maintenance only)
Score: 70/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 97, release rhythm 18, longevity 100
- inputs: {"age_days": 5164, "days_push": 22, "days_rel": 390, "gap_med": 164.5, "n_releases_24m": 3}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1176, forks 155 (observed 2026-08-28T04:03:52.550714+00:00)

## What it is
A dependency-free JavaScript library for parsing and serializing iCalendar (RFC 5545), jCal, vCard (RFC 6350), and jCard data. Originally built as a libical replacement for the Mozilla Calendar Project, it works in both Node.js and browsers and includes recurrence iteration and timezone support.

## Use cases
- parse .ics calendar files in javascript
- convert between ics and jcal formats
- parse vcard contact data in the browser
- calculate recurring event occurrences from RRULEs
- validate iCalendar data in a web app
- build a calendar feed reader in node
- handle timezones when parsing ics events

## When to choose
- you need standards-compliant iCalendar or vCard parsing in JavaScript
- you want a zero-dependency library usable in both browser and Node.js
- you need recurrence rule expansion or timezone handling for calendar data

## When to avoid
- you need to generate full-featured calendar server software with scheduling extensions beyond this library's scope
- you work in a non-JavaScript language where libical or native libraries are more appropriate

## Facets
- artifact type: library
- maturity: stable
- function: parser, serialization
- domain: parsers, developer-tools, web-development
- platform: browser, cross-platform
- tags: icalendar, vcard, jcal, jcard, rfc5545, rfc6350, calendar, contacts, recurrence, nodejs, javascript

## Member repositories
- kewisch/ical.js (main) score 70

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:52.550714+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:26:35.464450+00:00, confidence not recorded.
  - readme: https://github.com/kewisch/ical.js (fetched 2026-08-28T04:03:52.550714+00:00, sha 819e52547634)
  - homepage: https://kewisch.github.io/ical.js/ (fetched 2026-08-29T12:32:58.497948+00:00, sha 44136fa355b3)
  - registry_npm: https://registry.npmjs.org/ical.js (fetched 2026-08-29T12:32:58.506898+00:00, sha 00e11db5c0a1)
- Data as of 2026-08-30T08:39:29.467469+00:00.