The Roman CalendarYes, It’s Complicated!

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Roman CalendarPart 1: Roman year (easy)Part 2: Roman day and night

(easy)Part 3: Roman Month (most

complicated)

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KalendarsEarly Civs based calendar on

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

Where? Lunar cycle does not follow Earth

CycleUN proposed 13 months 28 days

each

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Anni 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. (doesn’t

matter when year starts) (Later Jan 1st)

PoG 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 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). From the founding of Rome.

Rome was founded in 753 bc by Romulus.

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

again. So he reformed the calendar.Now called Julian 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 ¼ days. (same as length now)

Leap day every 4th year.

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FYI: Pope Gregory: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.

Gregorian Calendar

PoG Part 2: Dies RomanusThe Roman dies began at sunrise.

(Prima Luce)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.)

Meridies (Noon) 6th hour (am/pm)Sunset: end of 12th hour.

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The Nox RomanaNox: 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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Part 3: Menses RomaniMenses Romani are difficult to

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

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

-- Nonae 9 days before the Ides

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Dies KalendaeThe days of the month were numbered.They counted DOWN until the K, N or I.Pridie = the day before the Kalends,

Nonae, or Idusa.d. = Ante diem = day beforeWeird: Pridie to us is 1 day before, to

them it was two days before. (tomorrow is two days away) [count today and tomorrow]

Octave: to us it is 7 days, to them it is 8

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Dies Kalendae

Also days marked with letters A – H

Each year a letter would be marked in RED and represented MARKET DAY

Market Day was called Nundiae (9th day)

PoG Example of Month: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

PoG 7 day week: Iulius Caesar 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 (Sol), Moon (luna) and planets.5 Planets: (day of _____)

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

names.

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Actual Roman Calendar

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