A lunar calendar is a calendar whose date indicates the moon phase.

This is normally done by having a month which corresponds to a lunation so that the day of month indicates the moon phase.

A lunar calendar may indicate the season as well as the moon phase, as the Hebrew calendar and Chinese calendar do. Such a calendar is a lunisolar calendar. But a lunar calendar need not do so. The Islamic calendar has a year which does not follow the seasons. Such a calendar is a pure lunar calendar.