Every 823 Years 捌佰貳拾參年才發生一次

捌佰貳拾參(823)年才發生一次的情形... 今年十月有五個禮拜五, 六, 及日. This month has 5 Fridays, 5 Saturdays, and 5 Sundays. This only happens every 823 years.