Roman Timekeeping

Like us, the Romans divided days into hours, or hora. Unlike us, and lacking access to precise mechanical clocks, the Romans divided days into hours of uneven, varying, and constantly fluctuating length, depending on the time of the year, the location of the timekeeper in the Empire, and the movement of the sun.

At the summer solstice, for example, the Roman day (in Rome) would have begun around 4:30am and ended around 7:30pm. At the winter solstice, when the days are the shortest, the Roman day would have begun much later (around 7:30am) and ended much earlier (around 4:30pm). Since the Roman day always contained 12 hours, the varying lengths of the day corresponded with varying lengths in each subsidiary hour. The night (or "evening," in the case of the Vipasca bronzes) also contained 12 hours, with lengths varying inversely with the length of the hours of the day.

William Smith, in his 1875 Dictionary of Greek and Roman Antiquities, provides us with the following explicatory tables:

Summer-Solstice.
Roman Hours.
Modern Hours.
1st hour
4 o'clock, 27 minutes 0 seconds
2d hour
5 o'clock, 42 minutes 30 seconds
3rd hour
6 o'clock, 58 minutes 0 seconds
4th hour
8 o'clock, 13 minutes 30 seconds
5th hour
9 o'clock, 29 minutes 0 seconds
6th hour
10 o'clock, 44 minutes 30 seconds
7th hour
12 o'clock, 0 minutes 0 seconds
8th hour
1 o'clock, 15 minutes 30 seconds
9th hour
2 o'clock, 31 minutes 0 seconds
10th hour
3 o'clock, 46 minutes 30 seconds
11th hour
5 o'clock, 2 minutes 0 seconds
12th hour
6 o'clock, 17 minutes 30 seconds
End of the day
7 o'clock, 33 minutes 0 seconds
Winter-Solstice.
Roman Hours.
Modern Hours.
1st hour
7 o'clock, 33 minutes 0 seconds
2d hour
8 o'clock, 17 minutes 30 seconds
3rd hour
9 o'clock, 2 minutes 0 seconds
4th hour
9 o'clock, 46 minutes 30 seconds
5th hour
10 o'clock, 31 minutes 0 seconds
6th hour
11 o'clock, 15 minutes 30 seconds
7th hour
12 o'clock, 0 minutes 0 seconds
8th hour
12 o'clock, 44 minutes 30 seconds
9th hour
1 o'clock, 29 minutes 0 seconds
10th hour
2 o'clock, 13 minutes 30 seconds
11th hour
2 o'clock, 58 minutes 0 seconds
12th hour
3 o'clock, 42 minutes 30 seconds
End of the day
4 o'clock, 27 minutes 0 seconds
Bill Thayer gives us a simple rule for translating Roman hours into their modern equivalents: "when we read 'the third hour, the sixth hour,' etc.... add 3, 6, etc. to 5:00 A.M.: The first hour, for example, runs from roughly 6 to roughly 7 A.M.; and the ninth hour from roughly 2 to roughly 3 P.M."

The times given for allowing men and women into the Vipasca mines, therefore, would have varied according to the factors mentioned above. At the summer solstice, women would have been allowed in from about 4:30am to noon; men would have begun entering at 1:15pm and socialized, should they have so chosen, until 9 or 10pm.

For more information, feel free to check out this very helpful page on Roman timekeeping.