In the Hellenistic system the weekdays were named after the 7 classical planets (Saturn, Sun, Moon, Mars etc), which planet is commemorated by the day we call Friday?
Classical planet to Earth to furthest, as the Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn. In addition the day was divided into 7 hour intervals, each ruled by one of the planets, although the order was staggered (see below). The first hour of each day was named after the ruling planet, giving rise to the names and order of the Roman seven-day week. Modern Latin-based cultures, in general, directly inherited the days of the week from the Romans and they were named after the classical planets; for example, in Spanish "Miércoles" is Mercury, and in French "Mardi" is Mars-day. The modern
Names of the days of the week - see понедельник Thing (Assembly), of which god Tyr/Ziu was the patron. Mid-week "or" Middle The day between two fasts "(An Dé idir dhá aoin, contracted to An Déardaoin)" (Christianity) The Fast or Fasting Day (Christianity) Good Friday or Preparation (Christianity) "Shabbat" (Jewish Sabbath) 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