calendar

In a dsh environment, calendar and scheduling work usually means spinning up an external API service or dragging in a heavy dependency chain. dsh-calendar folds all of that into a single self-contained npm package with zero runtime dependencies: it speaks standard CalDAV (REPORT, PROPFIND, GET, PUT, DELETE) to Google Calendar, iCloud, Nextcloud, or any self-hosted server, and handles listing, creating, updating, deleting, and searching events end-to-end. Credentials are resolved from environment variables, the dsh credential service, or a local chmod-0600 file, and a built-in redact helper ensures secrets never leak into logs.

What sets it apart from a thin CalDAV wrapper is the full Chinese-calendar context and a from-scratch RFC 5545 recurrence engine. Lunar month conversion is computed astronomically via Meeus truncated new-moon and solar-longitude series, covering 2000 through 2100 by construction including leap months. Traditional holidays such as Spring Festival, Qingming, Dragon Boat, Mid-Autumn, Lantern, Qixi, Chongyang, and the lunar year-end festival are built in, and the sexagenary cycle with zodiac is anchored at Lichun. The RRULE expander supports every FREQ from SECONDLY through YEARLY plus ordinal BYDAY, BYSETPOS, EXDATE, and RDATE; editing or deleting a single occurrence writes a RECURRENCE-ID override and never touches the series master. Conflict detection flags overlapping spans across timed, all-day, and recurring instances. The timezone engine embeds IANA rules (2000 through 2100) with deterministic DST fold and gap resolution, so wall-clock to UTC conversion needs no external library.

The full cal_* tool chain (cal_list, cal_create, cal_update, cal_conflicts, cal_holidays, cal_remind, and more) mounts directly onto dsh ctx.tools, and cal_remind output plugs straight into schedule_create for session-local reminders in the event timezone. It is well suited for developers building scheduling assistants inside dsh, teams that need Chinese lunar-calendar and holiday context, and anyone managing multiple CalDAV sources without wanting to stand up a separate backend service.