Description: 历法是一种用来计算时间，特别是用来确定季节的系统。历法通常以日、周、月和年为单位。它是一个基于天体（月亮、太阳、恒星）周期性运动的抽象系统。历法自古就有。月亮和太阳这两个天体有着很容易识别的周期性运动。于是，人们随着日、周、月和季节的流逝，可以感受到明显的变化。历法既可以基于月相周期（即阴历），也可以基于太阳年（即阳历），还可以在阴历中增加一些天数以与太阳年相匹配（即阴阳历）。世界各地的历法种类繁多，源自当地的天文学传统。

Related Terms:

• Lunar Phase
• Seasons
• 年

Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher
The translation of this term and its definition is still awaiting approval

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