Saturday (i/ˈsætərdi/ or /ˈsætərdeɪ/) is the day of the week following Friday and preceding Sunday. Saturday is the seventh and therefore last day of the week according to many commonly used calendars, but it is the second-to-last (sixth) day of the week according to ISO 8601 (see below). The Romans named Saturday dies Saturni ("Saturn's Day") no later than the 2nd century for the planet Saturn, which controlled the first hour of that day, according to Vettius Valens. When the day's name was introduced into English and other Germanic languages, however, the name was selected as a calque of the god Saturn, after whom the planet was named. The name was introduced into English no later than the tenth century, when the day was referred to as "Sæternes dæge" in an Old English translation of Bede's Ecclesiastical History of the English People. Prior to that, the old English name was sunnanæfen ("sun" + "eve"). The weekday heptagram, i.e., the association of the days of the seven-da...