Lunar and Solar Calendar Converter

Convert a date in the Chinese calendar

This converter maps a Gregorian date to its corresponding date in the Chinese lunisolar calendar, or converts a Chinese lunar year, month, and day back to Gregorian. It is intended for Chinese calendar dates; it is not a general converter for every lunar calendar used around the world. English labels identify the input mode, while returned calendar records and traditional names may appear in Chinese.

The Chinese calendar is lunisolar: lunar months follow the Moon, while the calendar also accounts for the solar year. Because twelve lunar months do not always line up with a solar year, some years include an intercalary, or leap, month. That month is distinct from the ordinary month with the same number. For example, in 2023 the second month and leap second month begin on different Gregorian dates: February 20 and March 22 respectively. A source that says only “second month, day one” is therefore incomplete if that year has a leap second month.

For a Gregorian input, the result includes the Chinese lunar date. For a lunar input, the result includes the Gregorian date. Additional fields can show the year’s stem-branch and zodiac combination, month and day stem-branch names, a weekday value, and a solar term or festival when the calendar library returns one. The weekday appears as an index from 0 to 6, where 0 is Sunday and 6 is Saturday. Solar terms and festival names may be displayed in Chinese.

The lunar-to-Gregorian year selector covers 1900 through 2099. The Hong Kong Observatory publishes comparison tables for 1901–2100, including a 2026 table; these are useful for checking a date independently. Its notes also explain that some far-future new moons or solar terms close to midnight can produce a one-day date discrepancy between forecasts or tables.

Choose the date system you already know

1. Set the direction. Choose Solar to Lunar when your source gives a Gregorian date such as 2026-02-17. Choose Lunar to Solar when the source gives a Chinese lunar year, month, and day.
2. Enter the date fields. In Solar to Lunar, select the Gregorian date. In Lunar to Solar, select a lunar year, month, and day. Years are available from 1900 to 2099 in this direction.
3. Mark a leap month precisely. When the selected year has a leap month, the month list includes a separate “Leap” entry after the matching ordinary month. Use the leap entry only when the original record explicitly identifies it as a leap month.
4. Read both dates and supporting fields. The larger date is the converted result and the smaller line retains the other calendar date. Optional cards show stem-branch names, weekday index, and any solar term or festival returned for that date. Use the copy control to copy the displayed date details.

For example, checking the two first days of the ordinary second month and leap second month in 2023 yields different Gregorian dates: 2023-02-20 and 2023-03-22. Keep “leap” attached to the date when saving or sharing it.

Common date-entry questions

Check the record and the date range

• The lunar-to-Gregorian year selector is limited to 1900–2099. Although the Gregorian date field does not present the same visible year list, the page does not state a verified coverage range for every historical or future Gregorian date.
• This is a day-level date conversion. It does not take a time of day or a location as input, and its result should not be treated as an authoritative historical chronology or precision astronomical determination.
• Calendar records and traditional field names may be Chinese even when the interface labels are English. If a Chinese source is ambiguous about leap-month status, confirm the original record before relying on a reverse conversion.
• For a historical, ceremonial, legal, or otherwise consequential date, compare the result with an appropriate official calendar or archival source. The Hong Kong Observatory notes that certain far-future lunar-month or solar-term dates may differ by one day when the underlying event is close to midnight.