Used by many cultural s throughout history, lunisolar calendars are used to indicate the date in the form of both the Moon phase and the time of the solar year. It is worth noting that the use of a lunisolar calendar provides an indication of the season. If considering a sidereal year, then the calendar will predict the constellation near which the full moon may occur. The lunisolar calendar divides the year into months, but because of the inconsistency between the lunar and solar year, every second or third year is an embolismic year, which adds a thirteenth intercalary, embolismic, or leap month.

In the lunisolar calendar, each of the months are based upon the moon phases. To account for the drift between seasons, the solar year, and the lunar year, lunisolar calendars begin by taking the lunar calendar and adding in specific amounts of time to bring the calendar into alignment with the solar year and seasons. These changes to bring the calendar into alignment might not be perfect, but it allows for some sort of resemblance of alignment with the solar year.

Famous lunisolar calendars used throughout history include the Hebrew, Jain, Buddhist, Hindu and Kurdish as well as the traditional  Burmese, Chinese, Japanese, Tibetan, Vietnamese, Mongolian and Korean calendars. There are a plethora of societies throughout history that have used this type of calendar, but those are a few that you might be more familiar with.

If you’re curious about what a pure lunar calendar is and what it looks like, then feel free to take a look at our article here. It provides a great opportunity to look at the differences in the two systems.

If you’re curious about the lunisolar calendar in India, check out this medium article. For those curious about the use of a lunisolar calendar in China, there is some history here.