Wiktionary
n. (plural of quarter day English)
Wikipedia
In British and Irish tradition, the quarter days were the four dates in each year on which servants were hired, school terms started, and rents were due. They fell on four religious festivals roughly three months apart and close to the two solstices and two equinoxes.
The significance of quarter days is now limited, although leasehold payments and rents for land and premises in England are often still due on the old English quarter days.
The quarter days have been observed at least since the Middle Ages, and they ensured that debts and unresolved lawsuits were not allowed to linger on. Accounts had to be settled, a reckoning had to be made and publicly recorded on the quarter days.
Usage examples of "quarter days".
The Earth rolls around the sun, three hundred and sixty-five and a quarter days a year, for year after year.