3 October is Gaecheonjeol in Korea, literally “the day the sky opened”. It commemorates the legendary founding of Gojoseon by Dangun, and it is the Korean national day that grew out of a rite of heaven worship.
In 2026 the seventh lunar month is a short one — just 29 days, with no thirtieth day — so in the Taiwan region the ghost gate closes early, late on 10 September. One small difference in the calendar pulls on a whole order of ghost month, the Zhongyuan rite and the Pudu offerings.
On 22 September this year, Japan gets a day off out of nowhere: by law, a day sandwiched between two public holidays automatically becomes a holiday. In the very same week, China, Korea and the Taiwan region of China all mark the fifteenth day of the eighth lunar month. One “free” day off leads to the calendar East Asia shares.
On September 25, 2026, China, Korea, Taiwan and Japan all celebrate the same full moon — the Mid-Autumn Festival, Chuseok and Jūgoya. Why does half of East Asia keep time by the moon? A look at the lunisolar calendar, the month pillar of Ba Zi, and three ways to celebrate one moon.
