Calendar Generator

Generates Google Calendar‑compatible .ics files from structured event data.

Install

openclaw skills install ics-generator

ics‑generator

When to use

When you need to convert a schedule, study plan, or task list into an iCalendar (.ics) file that can be imported into Google Calendar or any other iCalendar‑compatible client.

Workflow Overview

Collect structured events – each event must contain: - summary (string) - description (string, optional) - start (ISO‑8601 date/time or JS Date) - end (ISO‑8601 date/time or JS Date) - colorId (Google Calendar colour ID, optional)
Chunking / sequential dates - First chunk – supply the intended start date (e.g., 2026‑05‑31T09:00:00Z). - Subsequent chunks – pass the last date of the previous chunk (via the lastDate field). The skill will automatically shift the next chunk’s start date forward by one day, guaranteeing a clean “one‑day‑gap” between chunks.
Run the skill – invoke the run function exported by index.js with the event array and optional lastDate.

Implementation Notes

Feature	Details
Google‑Calendar compatibility	Automatically injects the required headers:<br>`PRODID:-//Google Inc//Google Calendar 70.6//EN` <br>`CALSCALE:GREGORIAN`
UTC enforcement	All start/end times are normalized to UTC and formatted as `YYYYMMDDTHHMMSSZ`. Google Calendar accepts this exact format without further conversion.
Unique identifiers	Each event receives a UUID‑v4‑derived UID (`event-<uuid>`) so calendar clients can correctly sync updates.
Color handling	If a `colorId` is supplied, it’s added as `X‑GOOGLE‑CALENDAR‑COLOR:<id>` inside the VEVENT block.
Output	Returns a complete `.ics` string wrapped in `BEGIN:VCALENDAR … END:VCALENDAR`. Every `VEVENT` ends with `END:VEVENT` and the final block ends with `END:VCALENDAR`.
Dependencies	Node ≥ 20 (for `crypto.randomUUID()`). No external npm packages—pure JavaScript plus Node’s built‑in `crypto` module.
License	MIT – free to copy, modify, and share.

Why the specific `PRODID` / `CALSCALE`?

From community feedback, Google Calendar only imported the generated file when those exact values were present. A generic PRODID caused the “Unable to launch event” error; CALSCALE:GREGORIAN tells Google Calendar which calendar system to assume (Gregorian), which is required for proper time‑zone handling.