Holdnaptár

Holdnaptár is a Hungarian term that translates to "moon calendar." It refers to a calendar system that is based on the cycles of the moon. Unlike a solar calendar which is based on the Earth's orbit around the sun, a lunar calendar tracks time by observing the phases of the moon as it orbits the Earth.

The most common type of lunar calendar is based on the synodic month, which is the time it takes for the moon to complete one cycle of phases from new moon to new moon, approximately 29.5 days. Over a year, a purely lunar calendar would have about 354 days, which is shorter than a solar year. This difference means that holidays and observances tied to a lunar calendar would drift through the seasons over time.

Historically, many cultures have used lunar or lunisolar calendars. Lunisolar calendars attempt to reconcile lunar cycles with the solar year by adding intercalary months or days periodically. The traditional Hungarian calendar, while primarily solar, may have incorporated elements or folklore related to lunar observations, especially in agrarian societies where lunar phases were believed to influence planting and harvesting.

In modern contexts, "holdnaptár" can refer to various calendars that emphasize lunar phases. This might include calendars used for astrological purposes, tracking specific moon phases for agricultural activities, or simply as a point of cultural or traditional interest. The concept remains tied to the observation and prediction of the moon's changing appearance in the night sky.