Sunday is the day of the week between Saturday and Monday. In most Western countries, Sunday is a day of rest and a part of the weekend, whereas in much of the rest of the world, it is considered the first day of the week.
For most observant adherents of Christianity, Sunday is generally observed as a day of worship and rest, recognising it as the Lord's Day and the day of Christ's resurrection; in the United States, Canada, Japan, the Philippines as well as in most of South America, Sunday is the first day of the week. According to the Hebrew calendar and traditional calendars (including Christian calendars) Sunday is the first day of the week; Quaker Christians call Sunday the "first day" in accordance with their testimony of simplicity. The International Organization for Standardization ISO 8601, which is based in Switzerland, calls Sunday the seventh day of the week.