About Lunar — Important Lunar Dates

What is Lunar?

Lunar is a free, browser-based important lunar dates tracker for festivals and dates celebrated on the lunar calendar. It solves the common problem that a lunar festival — e.g. Mid-Autumn on Month 8, Day 15 — falls on a different solar-calendar date every year. You enter the lunar month + lunar day (e.g. 8 / 5) and Lunar shows you the correct solar date for every year.

How It Works

Lunar input, solar output: Enter a name plus the lunar month (1–12) and day (1–30) — e.g. Mid-Autumn 8/15, Dragon Boat 5/5 — and optionally mark it as a leap-month date.
Real lunar math: The lunar data (1900–2100, Purple Mountain Observatory / Hong Kong Observatory) is powered by the MIT-licensed chinese-lunar library (vendored in TypeScript) plus a custom lunar2solar on the same DATD table. Short 29-day months clamp, leap-month birthdays only appear in years with that leap month.
Next birthdays at a glance: The dashboard shows the next solar celebration date for each person (with day-countdown) and the next several years.
Google Calendar as the repeating cycle: Since Google Calendar's RRULE can't express "every 8th-month 5th-day," Lunar creates one event per lunar year at the exact converted solar date. Each event has a 9:00 AM reminder and a stable per-year slug, so the "lunar calendar is the repeating cycle" via many precise solar events.
Offline backups: Export the whole schedule as a standard .ics calendar file for Apple Calendar, Outlook, or Thunderbird.

Google Calendar Cloud Sync (Optional)

Lunar can optionally use your Google Calendar as a cloud database so your lunar birthday schedule stays in sync across all your browsers and devices. When you connect your Google account:

The App creates a dedicated, app-scoped secondary calendar (named "Lunar Dates" by default) that only the App uses.
Each lunar date becomes many per-year events (one per lunar year, next 15 years), each with a permanent per-year slug identifier.
Access is strictly limited to secondary calendars created by this App. The App does not read, modify, or delete your primary calendar, emails, contacts, Drive files, or any other Google data.

Connecting your Google account is entirely optional. Without it, the App works fully offline using your browser's local storage.

Data & Privacy

The App is a static client-side web application with no servers or databases of its own. Your birthday data lives in your own browser's local storage and, if you opt in, inside a calendar in your own Google account that you fully control. The App does not sell or share your data. For full details, please read our Privacy Policy.

Quick Facts

App name

Lunar