Three systems · one familiar phrase
What is a lunar calendar?
“Lunar calendar” can mean a calendar whose months follow lunar cycles, a lunisolar calendar that also stays aligned with seasons, or an astronomical chart that displays Moon phases alongside civil dates. These are related concepts, not interchangeable systems.
Convert a Gregorian date
- Chinese lunisolar
- 20 Ninth Month 2026(bing-wu)
- Islamic civil (tabular)
- 17 Jumada I 1448 AH
- Hebrew lunisolar
- 18 Heshvan 5787
These are daytime civil-date equivalents. The Islamic civil option follows a tabular calendar; observational Islamic dates follow the crescent declaration used by a community. Hebrew days begin at sunset. Chinese lunar months include leap months to stay aligned with the seasons.
Three calendar concepts
- Moon-phase calendar
- Shows astronomical phases and events against dates in a civil calendar.
- Lunar calendar
- Defines months primarily from lunar cycles; rules differ between named calendar traditions.
- Lunisolar calendar
- Uses lunar months and an adjustment system, such as leap months, to remain connected to the solar year.
Civil dates
Phases and calendar dates
An astronomical Moon-phase calendar uses Gregorian dates and a selected IANA time zone. Chinese, Islamic, Hebrew, Mongolian and other named calendars follow their own month, observance and conversion rules.
UTC
Why time zone matters
A phase event is one instant worldwide, but its civil date can differ by location. The phase schedule shows each event in your selected time zone.