The Equinoctial Hour in Antiquity: Which Hour is Ours?

Evan Boxer-Cook

Seasonal Hours - Popular Time

“The first and second hour of the day exhaust the clients who pay respects to their patrons; the third exercises the lungs of the noisy lawyers. Until the fifth Rome

peruses various activities. The sixth brings rest to the fatigued; the seventh ends

this rest. The eighth suffices for the games of the oily palaestra; the ninth

commands us to drop onto the set-up couches.”

Martial, Epigrammata 4.8 (c. 90 CE)

Seasonal Hours - Popular Time

The Equinoctial Hour

The Equal Hour

• A unit of measurement;

strictly cardinal

• No institutionalized zero point

• Capacity to express both duration and position
• Backed by infrastructure

The Equinoctial Hour’s Transmission to Greece

For the Greeks learned about polos, gnomon, and the twelve parts of the day from the Babylonians

​

πόλον μὲν γὰρ καὶ γνώμονα καὶ τὰ δυώδεκα μέρεα

τῆς ἡμέρης παρὰ Βαβυλωνίων ἔμαθον οἱ Ἕλληνες

​

Herodotus’ Histories (c. 425 BCE)

Evidence from Babylonian horoscopes suggests that seasonal hours (Simanu) weren’t known in Babylonia until 125–69 BCE.

Olympia dial, 350 BCE

Oropos dial, terminus post quem 4th century BCE

Phalara dial, terminus ante quem 270 BCE

Parokia dial, late 3rd or early 2nd century BCE

British Museum dial, terminus ante quem 2nd century BCE

• Seasonal hours appear in the Greek material record by the mid third century BCE.
• (Postage, civil organization, astronomy)

​

• Equinoctial hours were relegated to very specific niche cases requiring the articulation of daylight duration.

​

• Sets the scene for a later Roman resurgence of the equinoctial hour.

• The 1st–3rd centuries CE see an increased usage of the equinoctial hour.
• Catalyzed by the invention of the water clock and the establishment of the legal equinoctial day.

Pliny the Elder (1st century CE):

Duration of daylight, compared across dates and latitudes

Ptolemy (2nd century CE):

Timing of astronomical events (zeroed at sunrise, noon, sunset, or midnight)

Galen (3rd century CE):

Duration of fevers and cycles of disease (zeroed at onset of fever)

“the longest day covers 12 8/9 equinoctial hours at Meroe, but 14 hours at Alexandria, 15 in Italy, and 17 in Britain”

Pliny the Elder, Historia Naturalis 2.186

The equinoctial hour appears in technical writing, but to what extent was it known/used popularly?

The Daylight Triangle

Roman hemispherium c. 1st century CE, Musei Vaticani, Inv. MV.2439.0.0, Vatican City.

The objective reference time of the equinoctial hour contextualizes the seasonal hour

Menologia Rustica

Jan

Day: 9

Night: 14

Feb

Day: 10

Night: 13

Mar

Day: 12

Night: 12

Public standards;

Almanacs.

​

Agricultural focus

Daylight, planting seasons

​

Mensis

Decemb(er).

Dies XXXI,

Non(ae) quint(anae).

Dies hor(arum) VIIII,

nox hor(arum) XV.

Sol Sagitt(ary).

Tutel(a) Vestâe.

ĥ̂iemps înitiu(m).

sive tropae

chimerin(ae).

Vin̂eas sterc(orant),

faba(m) seren̂tes,

materias

deicientes,

oliva(m) legent(es),

ìtem venan̂t(ur).

Saturnalia.

December

31 days

Nones on the fifth day

Hours of daylight: 9

Hours of night: 15

Sun in Sagittarius

Tutelary deity: Vesta

Beginning of Winter

That is, the Winter solstice

They fertilize the vineyards,

plant the beans,

cut down lumber,

collect olives,

and also hunt.

Saturnalia

Menologium Rusticum Colotianum

Menologium Rusticum Vallense

Funerary Epigraphy

Ragonia /�Septimilla /�vixit a(nnis) XX /�die I hor(is) XI.

​

Ragonia Septimilla lived for 20 years, one day, and 11 hours.

​

(Ostia, undated)

Hic infans qui hic positus est no/�mine Marcianus vixit ann(is) VII di(e)b(us) /�XLIIII hor(is) noctis IIII.

​

The infant named Marcianus who was placed here lived for 7 years, 44 days, and 4 hours of the night.

​

(Rome, 351–400 CE)

D(is) M(anibus) /

L(ucio) Titedio Fortunatiano iu<v=B>eni /

probissimo qui vixit annis(!) XXXV /

menses duo dies VI [h(oras)] XIII Titedia /

Memmia coniu(n)x et Titedius /

Titianus co<g=C>natus homini /

rarae innocentiae per() /

b(ene) m(erenti) p(osuerunt).

​

To the Divine Manes. Lucius Titendius Fortunatianus, a most honest young man who lived for 35 years, 2 months, 6 days, and 13 hours. Titedia Memmia his wife and Titedius Titianus his relative set this up for a well-deserving man of rare innocence.

​

(Rome, undated)

Iuliu{i}s Ia/

nuarius /

v(ixit) h(oras!) XC /

h(ic) s(itus) e(st).

​

Julius Lanuarius lived for 90 hours. He lies here.

​

(Numidia, undated)

Conclusions

Use into the 2nd and 3rd centuries CE?

Use of the equinoctial hour diffused beyond the scientific

Evidenced non-technical presence and potential for broad, popular awareness

Approximately 80% of the Roman population was involved in agriculture

The Equinoctial Hour in Antiquity: Which Hour is Ours?

Evan Boxer-Cook