What’s the difference between lunar and solar calendars?
Solar calendars are based on the year – the period of time Earth takes to orbit the Sun, and therefore the time the Sun takes to return to its position in the sky relative to the background stars, equivalent to approximately 365.25 days. Lunar calendars, meanwhile, are based on the lunar month – the period of time between successive new or full Moons, when Earth, the Moon and the Sun are aligned with each other. A lunar month is equivalent to 29.53 days. The Moon takes just 27.32 days to orbit Earth – the extra time is needed for the Moon to ‘catch up’ with the relative position of the Sun in the sky.