Time in Rome

Italy adopted a single national time on November 1, 1893, defined by the 15° east meridian, which Italians call the Etna meridian because it passes close to the volcano in Sicily. Before that, Rome kept its own local mean time, set at the Collegio Romano observatory, and cities such as Turin, Florence and Naples each had theirs. The same national clock is used in Vatican City and San Marino.

Italy first used summer time in 1916, dropped and reintroduced it several times, and has applied it every year since 1966. It now follows the European Union calendar, changing on the same Sunday mornings as Paris and Berlin.

Rome lies at 41.9° north and 12.5° east, a little west of the Etna meridian, so solar noon falls near 12:10 PM in winter and 1:10 PM in summer. At the June solstice the sun rises around 5:35 AM and sets near 8:50 PM, a little over 15 hours of daylight. In December sunrise is about 7:35 AM and sunset around 4:40 PM, about 9 hours.

Offices generally work 9:00 to 18:00, with shops in many areas closing for a break in the early afternoon, and Euronext Milan trades from 9:00 to 17:30. New York is six hours behind most of the year, so 4:00 PM in Rome is 10:00 AM in New York. Los Angeles is nine hours behind, which means only the first California working hour, 8:00 to 9:00 AM, falls within the Roman working day at 5:00 to 6:00 PM. The CET to PST page lists every hour, including the weeks when the gap is eight hours.