太陰曆係同月亮嘅運動（月相）同步，例如伊斯蘭曆。太陽曆係依照同太陽運動有關嘅季節變化同步，例如伊朗曆。陰陽曆係合併咗月亮和太陽嘅變化，例如農曆、印度曆或者希伯來曆。亦都有啲曆法系統似乎係同金星嘅運動同步，例如一啲古埃及曆法，同金星出現係赤道上面嘅時間同步。
The lunar calendar is synchronized with the movement of the moon (moon phases), such as the Islamic calendar. The solar calendar is synchronized with the seasons related to the movement of the sun, such as the Iran calendar. A lunisolar calendar is a combination of changes in the moon and the sun, such as the lunar calendar, the India calendar, or the Hebrew calendar. There are also calendar systems that seem to be synchronized with the movement of Venus, such as some ancient Egypt calendars, and the appearance of Venus is synchronized above the equator.