Wednesday "Germanic Mercury". The Latin name dates to the late 2nd or early 3rd century. It is a calque of Greek ("heméra Hérmou"), a term first attested, together with the system of naming the seven weekdays after the seven classical planets, in the "Anthologiarum" by Vettius Valens (c. AD 170). The Latin name is reflected directly in the weekday name in most modern Romance languages: "Mércuris" (Sardinian), "mercredi" (French), "mercoledì" (Italian), "miércoles" (Spanish), "miercuri" (Romanian), "dimecres" (Catalan), "Marcuri" or "Mercuri" (Corsican). In Welsh it is Dydd Mercher, meaning Mercury's Day. The German name for the day, "Mittwoch" (literally: "mid-week"), replaced the
Names of the days of the week Names of the days of the week The names of the days of the week in many languages are derived from the names of the classical planets in Hellenistic astrology, which were in turn named after contemporary deities, a system introduced by the Roman Empire during Late Antiquity. In some other languages, the days are named after corresponding deities of the regional culture, either beginning with Sunday or with Monday. In the international standard ISO 8601, Monday is treated as the first day of the week. Between the 1st and 3rd centuries, the Roman Empire gradually replaced the eight-day Roman