Perpetual Calendar

Features

• Monthly Gregorian-lunar grid: each cell carries the lunar day, solar terms and festivals.
• Click any day for the full almanac: four pillars, elements, do/don't lists, clashes and deity directions.
• Hourly fortune: all twelve two-hour periods with their own suitable and taboo activities.
• Official holidays and swap workdays marked on the grid (data for 2013–2026) with a monthly summary.
• Two-way Gregorian-lunar conversion with leap-month support; solar-term table down to the minute.
• Runs fully offline in your browser on the open-source lunar-javascript (MIT) data — no requests, no uploads.

How to use

• The page opens on today. Each grid cell stacks the lunar day, solar terms and festivals under the Gregorian date; Off/Work badges mark official holidays and swap workdays.
• Click any cell to load that day's almanac below; use the month buttons or the date box to move to any month between 1900 and 2100.
• To find the Gregorian date of a lunar birthday, switch the converter to Lunar → Gregorian and tick the leap month if the lunar year has one.
• The festival shortcut row lists this year's Gregorian dates of Spring Festival, Mid-Autumn and more — click one to jump there.

FAQ

How are the lunar dates computed — can I trust them?

The open-source lunar-javascript library derives each month from new-moon and mid-qi astronomy (Purple Mountain Observatory data): the new-moon day is the 1st, the winter-solstice month is month 11, and a month without a mid-qi becomes the leap month. Within 1900–2100 it matches printed Chinese calendars; the bundled holiday schedule covers the announced 2013–2026 arrangements.

Are the do/don't lists and hourly fortune scientific?

No. They come from the folk election-of-auspice system built on stems and branches, the twelve officers and the 28 mansions. This page faithfully renders the traditional rules for cultural reference; please use modern criteria for real decisions.

Why do some years show no Off/Work badges?

China's holiday and swap-workday schedule is announced yearly by the State Council. The built-in dataset covers 2013–2026; outside that range the page shows festival names only and never guesses.

How are leap months handled in the converter?

When the selected lunar year contains a leap month, the month list shows it as an extra "leap month N" option; Gregorian → lunar results state explicitly whether the date falls in the leap month. Which month is doubled is decided by the no-mid-qi rule.

Are the dates I look up recorded?

No. The page is static; every calendar and almanac value is computed inside your browser, and no request goes to our server. It keeps working offline (except third-party ad slots).

About

This perpetual calendar puts three things on one page: a Gregorian-lunar month grid (with solar terms, festivals and holiday marks), a daily almanac panel for the selected day, and a two-way calendar converter.

Lunar and almanac data come from the open-source lunar-javascript library (MIT); the holiday schedule is its consolidation of State Council announcements. No backend service is involved.

More tools on this site

• World Time Difference
• Speed Test
• IP Address Lookup
• PDF Toolkit
• Text Diff & Review
• Unicode Emoji Table

Runs fully in your browser · lunar data by lunar-javascript (MIT) · free · 中文/繁體/English