The Roman CalendarThe Roman CalendarYes, It’s Complicated!

KalendarsKalendarsEarly Civs based calendar on

Lunar cycle. 13 months, 28 days each Lunar cycle is still used:

Where? Lunar cycle does not follow Earth

Cycle

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Anni RomaniAnni RomaniThe Romans were not good at

keeping track of years. They got better as time went on.

Early: Only 10 months per year. The winter months (Jan and Feb)

were not counted on the calendar as days.

Numa Pompilius added January and February to the end of the year.

March 1st was New Year Day.

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So month names were misnomers.They were off by two months:

October was the 10th month and not 8th month.

Year was still only 355 days. So occasionally, they added leap

day to end of the year: Feb 29th

Occasionally they added a leap month (intercalenary) containing as many days as they needed to get the year back on schedule.

The Pontifices determined all this.

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Annus Dating SystemAnnus Dating SystemThe Romans did it two ways:a) According to the names of the

two consuls. Consuls ruled for 1 year terms. (You may consult internet for entire list of consuls.)

b) Years since the founding of Rome = Ab Urbe Conditu (AUC).

Rome was founded in 753 bc by Romulus.

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Iulius Caesar Reforms Iulius Caesar Reforms CalendarCalendarBy IC’s time the calendar was way off

again. So he reformed the calendar.To set year correct: year 46 bc was

455 days long. “Last Year of Confusion”

Starting in 45 bc, the year was designated as 365 ¼ days long. Days were added to months so = 365 days. (same as length now)

Leap day every 4th year.

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FYI: Gregorian calendar:FYI: Gregorian calendar:Despite Caesar’s best effort, the

year was off by 11 minutes a year. Which adds up to 1 day every 134 years.

So by Pope Gregory XIII in 1582 the year was off by ten days.

He reset the calendar and added new rules for when NOT to have leap days to keep the calendar in synch.

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The Roman DiesThe Roman DiesThe Roman dies began at sunrise. Daylight was divided into 12 horas

(hours). Problem?Summer hours were longer than

Winter hours. (PGH on the Solstice:

Summer 75 minute hour, Winter 46 minute hour.)

Noon: 6th hour, Sunset: end of 12th hour.

Meridies: the term for Noon: am pm

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The Roman NoxThe Roman NoxNox: harder to tell time at night.Most people stayed in and went

to bed early.Nox divided into 4 vigils

(watches)

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Menses RomaniMenses RomaniMenses Romani are difficult to

follow.3 main days:--Kalends 1st day of the month-- Ides 13th day of month

15th day of Month in March, July, October and May

-- Nones 9 days before the Ides

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Dies CalendaeDies CalendaeThe days of the month were numbered.They counted DOWN until the K, N or I.Pridie = the day before the K, N, or Ia.d. = Ante dies = days before

Also days marked with letters A – HEach year a letter would be marked in

RED and represented MARKET DAYMarket Day was called Nundiae (9th day)

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Example of Month:Example of Month:PoG

January , August or December

F 1: Kalends H 11: ad 3 I Jan

B 21: ad 12 K Feb

G 2: ad 4 N Jan A 12: Pridie Idus C 22: ad 11 K Feb

H 3: ad 3 N Jan B 13: Idus D 23: ad 10 K Feb

A 4: Pridie Nonae

C 14: ad 19 K Feb

E 24: ad 9 K Feb

B 5: Nonae D 15: ad 18 K Feb

F 25: ad 8 K Feb

C 6: ad 8 I Jan E 16: ad 17 K Feb

G 26: ad 7 K Feb

D 7: ad 7 I Jan F 17: ad 16 K Feb

H 27: ad 6 K Feb

E 8: ad 6 I Jan G 18: ad 15 K Feb

A 28: ad 5 K Feb

F 9: ad 5 I Jan H 19: ad 14 K Feb

B 29: ad 4 K Feb

G 10: ad 4 I Jan A 20: ad 13 K Feb

C 30: ad 3 K Feb

D 31: Pridie K Feb

7 day week: Iulius Caesar 7 day week: Iulius Caesar again: again: Romans did not really have weeks

like we do, but had market cycles: 8 or 9 days

Iulius Caesar changed the market cycles to be 7 days or an octave.

Each day was dedicated to the 7 main heavenly bodies.

Sun, Moon and planets.5 Planets: (day of _____)

Mars, Mercury, Jupiter, Venus, SaturnRomance Languages still use these

names.

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Actual Roman CalendarActual Roman CalendarPoG

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