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.
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
What this site provides
This site provides an astronomical Moon-phase calendar using 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 keeps a UTC source instant and converts it at the display boundary.