65. Calendar

See also 11. ALMANACS ; 396. TIME

analemma

a flgure-of-eight-shaped scale, for showing the declination of the sun and the equation of time for every day of the year. — analemmatic, adj.

bissextus

the twenty-ninth day of February, added to the calendar every four years, except in centenary years evenly divisible by 400, to compensate for the discrepancy between the arbitrary 365-day calendar year and the actual time of the solar year. — bissextile, adj.

calendographer

Rare. a person who makes calendars.

embolism

1. an intercalation of a day or days in the calendar to correct error.

2. the day or days intercalated. — embolic, embolismic, embolismical, adj.

heortology

the study of the origin, growth, meaning, and history of Christian religious feasts. — heortological, adj.

indiction

in the Roman Empire, the cyclical, fifteen-year fiscal period, used for dating ordinary events. Also called cycle of indiction. — indictional. adj.

intercalary

inserted into the calendar, as the twenty-ninth day of February in a leap year. — intercalation, n. — intercalative, adj.

lunation

the period of the moon’s synodic revolution, from the time of the new moon to the next new moon; one lunar month or approximately 29 1/2 days.

lustrum, luster, lustre

a period of five years.

menology

1. a list or calendar of months.

2. Eastern Orthodoxy. a calendar of all festivals for martyrs and saints, with brief accounts of their lives. Also Menologion.

2. a church calendar, listing festivals for saints.

metemptosis

the practice of eliminating the bissextile day every 134 years to adjust the date of the new moon. Cf. proemptosis.

neomenia

1. the time of the new moon or the beginning of the month.

2. a heathen festival at the time of the new moon.

proemptosis

the adding of a day every 300 and again every 2400 years to adjust the date of the new moon. Cf. metemptosis.