Sunday

Sunday (ⁱ/ˈsʌndeɪ/ or /ˈsʌndi/) is the day of the week following Saturday but before Monday. For most Christians, Sunday is observed as a day of worship and rest, holding it as the Lord's Day and the day of Christ's resurrection. Sunday is a day of rest in most Western countries, part of 'the weekend'. In some Muslim countries and Israel, Sunday is the first work day of the week. According to the Hebrew calendars and traditional Christian calendars, Sunday is the first day of the week, and according to the International Organization for Standardization ISO 8601 Sunday is the seventh and last day of the week. No century in the Gregorian calendar starts on a Sunday, whether its first year is considered to be '00 or '01. The Jewish New Year never falls on a Sunday. (The rules of the Hebrew calendar are designed such that the first day of Rosh Hashanah will never occur on the first, fourth, or sixth day of the Jewish week; i.e., Sunday, Wednesday, or Friday).

Etymology

Sunday, being the day of the Sun, as the name of the first day of the week, is derived from Hellenistic astrology, where the seven planets, known in English as Saturn, Jupiter, Mars, the Sun, Venus, Mercury and the Moon, each had an hour of the day assigned to them, and the planet which was regent during the first hour of any day of the week gave its name to that day. During the 1st and 2nd century, the week of seven days was introduced into Rome from Egypt, and the Roman names of the planets were given to each successive day.