Fixing the calendar

Lesson plan

3 class periods of about 45 minutes.

1. Day 1 · 45 min

   The year before Caesar

   1. 10 minutes: Read How the Romans fixed the year by Censorinus, passages 20.2 to 20.5. Students write down the first two stages of the Roman year: ten months of 304 days, then twelve months of 355.
   2. 10 minutes: Read passages 20.6 and 20.7. Students say who was given the task of inserting the extra months and what most of them did with it.
   3. 10 minutes: Read Where the months got their names by Macrobius, passages 12.39 and 14.1. Students note what went wrong with Romulus's year and what the priests did for the tax contractors.
   4. 15 minutes: Students start a timeline of the Roman year. At each stage they write who made the change (or that no one is named), on whose authority, and the reason given.

2. Day 2 · 45 min

   Caesar's reform

   1. 15 minutes: Read Censorinus, passages 20.8 to 20.10. Students check his sum for 46 BCE (355 + 23 + 67 = 445) and read the note on the manuscripts' 64 days to see how an editor decides which number to print.
   2. 15 minutes: Read Macrobius, passages 14.2, 14.3, 14.6 and 14.7. Students list what Caesar did, who helped him, and where Macrobius's figure for the last year of confusion differs from Censorinus's.
   3. 15 minutes: Read Censorinus 20.9 and Macrobius 14.12. Students explain why Caesar put the new days at the ends of the months and why he made them court days. The encyclopedia article The Julian calendar gives more background.

3. Day 3 · 45 min

   How the reform lasted

   1. 10 minutes: Read Macrobius, passages 14.13 to 14.15. Students explain the priests' new error, how Augustus corrected it, and why he had the arrangement engraved on bronze.
   2. 10 minutes: Read Censorinus, passages 21.7, 22.16 and 22.17. Students note how Censorinus counts the Julian years in 238 CE, which two months were renamed, and what happened to the months later emperors named after themselves.
   3. 10 minutes: Groups take one word each. Impact: what the old confusion cost, and whom it helped (20.7). Influence: who kept the reform going after Caesar. Change: what Caesar changed and what he kept in place, such as the festivals and the place of the extra day.
   4. 15 minutes: Each student writes a paragraph answering both halves of the unit question, citing both writers and naming one point where they disagree.

Read these sources

In this order. Each opens in Hearth Library with the original beside plain English, and a History tab on who made it and how far to trust it.

1. 1

   How the Romans fixed the year

   Censorinus, 238. Moderate.

   A short, orderly account crowded with numbers and Roman names; the notes explain the calendar terms.

   Questions, key terms and an activity

   civil year

   the calendar year that a city keeps by its own rules, as opposed to the natural year

   natural year

   the time the sun takes to complete its course, which brings the seasons back around

   full and hollow months

   the longer months were called "full" and the shorter ones "hollow"; in the ten-month year they had 31 and 30 days

   pontiffs

   the members of Rome's most important group of priests; their head was the chief pontiff

   consul

   one of the two chief officials of Rome, who served for one year; a year could be named after its consuls

   Olympiad

   a four-year period between the games at Olympia, counted from 776 BCE

   bissextum

   the extra day of Caesar's calendar, inserted every fourth year by counting the sixth day before the Kalends of March twice

   1. Comprehension According to Censorinus, who was given the task of inserting the extra months, and what did most of them do with it?
   2. Analysis Censorinus says that most Greek cities fitted their months to the moon, and that the Romans copied them when they had a year of 355 days. Why could a calendar built on the moon not stay in step with the sun, and how did Caesar's reform deal with the problem?
   3. Analysis (reliability) Censorinus wrote in 238 CE, nearly three hundred years after Caesar's reform, in a book he gave his patron as a birthday present. The scholar Teuffel thought he took most of his learning from Suetonius, and the manuscripts give one of his numbers differently from the figure editors print. What reasons do we have to trust his figures for the reform, and what reasons to be careful?
   4. Connection Read Where the months got their names. Macrobius makes the last year of confusion 443 days long, while Censorinus gives 445. Macrobius also tells of a later mistake by the priests, who inserted the extra day too often until Augustus corrected it; Censorinus does not mention this. When two ancient writers disagree or one leaves something out, what would you want to know about each before deciding whom to follow?

   Activity Students draw a timeline of the Roman year in the stages Censorinus gives, from Romulus's ten months of 304 days, through the twelve months of 355 days and the extra month every other year, to Caesar's year of 365 days and a quarter. At each stage they write who made the change (or note that he names no one), according to which authority, and the reason Censorinus gives. They then check his sum for the year 46 BCE (355 + 23 + 67 = 445) and read the note on the manuscripts' 64 days to see how an editor decides which number to print.

   For teachers · Worksheet for this source

2. 2

   Where the months got their names

   Macrobius, 400–430. Moderate.

   A learned dialogue crowded with Latin names, gods and earlier scholars; the notes explain the Roman calendar days and the priests.

   Questions, key terms and an activity

   Kalends

   the first day of a Roman month

   Nones

   the fifth or seventh day of a Roman month

   Ides

   a named day of each Roman month, eight days after the Nones

   flamens

   Roman priests, each of whom served one particular god

   auspices

   signs from the gods, at first read in the flight of birds, that an official watched for to learn whether the gods approved of an action

   intercalary month

   an extra month inserted from time to time to bring the calendar back into line with the seasons

   bissextum

   the extra day of Caesar's calendar, inserted every fourth year by counting the sixth day before the Kalends of March twice; it gave "bissextile," an old name for a leap year

   1. Comprehension According to Macrobius, how many months and days did the year of Romulus have, and what went wrong with it?
   2. Analysis For April, Macrobius gives two explanations of the name and then says which one it is right to believe. For May he reports several and does not choose. What kinds of evidence do his authorities use for their explanations? Why might he decide in one case and not in the other?
   3. Analysis (reliability) Macrobius wrote around 400 CE about Romulus, Numa and Julius Caesar. He puts these words in the mouth of Praetextatus, a real senator, at a gathering that is a literary fiction, and he names the earlier scholars he used. What can this passage tell us reliably, and what can it not?
   4. Connection Read How the Romans fixed the year. Censorinus reports that Varro took March from Mars because the Latins were warlike, not because Mars was Romulus's father, and May from the goddess Maia. Compare how Censorinus and Macrobius handle the disagreements among their authorities. Which writer tells you more clearly what he himself believes, and which approach is more useful to a historian?

   Activity Groups each take two or three months and make a chart with one row for every explanation of the month's name that Macrobius gives. For each row they write who held the view (such as Fulvius Nobilior, Cingius, Varro or Cornelius Labeo, or simply "some people"), the evidence offered, and whether that evidence comes from religion, from the sound of a word, or from politics. The class then puts the charts together and discusses which kind of evidence is most common and which month names rest on the firmest ground.

   For teachers · Worksheet for this source

To finish

Come back to the question: Why did the Romans need to reform their calendar, and how did the reform last? Ask students to answer it with evidence from at least two of the sources, and to say which source they trust most and why.

Standards

Students draw the Roman year in Censorinus's stages to Caesar's reform, chart Macrobius's rival explanations for each month's name with who held them, and check where the two writers' figures for the year of confusion disagree.

Go further

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Encyclopedia

The Julian calendar

Collection

Every source in Innovation in History