Since ancient times, man has been fascinated with the night sky. One object of particular fascination is the prominent moon. Because of the obvious cycles that the moon goes through, man started to use these lunar phases as a way to keep track of time. That is why most ancient calendars were lunar in nature.
On a lunar calendar, the phase that the moon is in determines what day of the month it is. Each moon cycle is known as a lunation, and there are roughly 12 lunations in one calendar year. A lunation is often times referred to as a synodic month. The traditional eight phases of the moon include
The cycle to go through all eight of these phases is precisely what is referred to as a lunation. In some lunar calendars the 1st day of the month is when the new moon appears. In others, the first day occurs when the lunar crescent is seen. This inconsistency is the first of many difficulties that arise when using the lunar calendar.
This calendaring system comes with inherent difficulties. Remember that the phases of the moon occur as the moon orbits around the earth, and that the earth is moving at the same time. The effect that these two orbits have on one another causes the moon to move at an inconsistent rate.
To figure out the precise movement of the moon, there is a lot of mathematical complexity involved. On top of that the time table is still variable in nature. It is for this reason that most calendaring systems have converted entirely over to the solar calendar. This way of measuring time is still not exact (as evidenced in Leap Year), but much more accurate nonetheless. Such calendars as the Chinese, Hebrew, and Hindu calendars use a lunisolar calendar.
This calendar is a combination of lunar and solar calculations. Today, the only calendar that is totally based on the lunar cycles is the Islamic calendar. This calendar is usually used for religious purposes and is used hand in hand with a solar calendar for ease of use.
Even though the lunar calendar is used so sparingly in today's world, there is still an intense interest in the phases of the moon. There are theories about how the changing moon affects the moods of human beings. There are myths about creatures that come out at specific times in the moons cycle.
There are scientific studies that show how the ever changing moon affects the earth itself. Our solar calendars still note the phases of the moon, and such holidays as Easter are still effected by the lunations that occur. There is no doubt that the lunar calendar is still a part of our lives whether we fully realize it or not.