Explainer | Why the Chinese calendar has ‘leap months’, when they fall and why they’re seen as unlucky
August 22, 2025 is the last day of the Year of the Snake’s second ‘sixth month’, but why are such lunar leap months considered inauspicious?
When it comes to measuring the passage of time, the Gregorian calendar tracks days, weeks, months and years to align with Earth’s orbit around the sun.
This means that, for most of the world, a year is a simple, solar affair: 365 days – or 366 every four years – for the Earth to complete its journey around the sun.
In contrast, the ancient Chinese also observed movements of the moon to guide their agricultural practices and cultural festivals.
According to the Chinese lunisolar calendar, the lunar month, the period from one new moon to the next, is roughly 29.5 days.
Twelve of these cycles equal 354 days; roughly 11 days shorter than the solar year.