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). Its Latin name dies Saturni ("Saturn's Day") entered into Old English as Saeternesdaeg. Saturday was named no later than the 2nd century for the planet Saturn, which controlled the first hour of that day according to Vettius Valens.