Tuesday is the day of the week between Monday and Wednesday. According to international standard ISO 8601, Monday is the first day of the week; thus, Tuesday is the second day of the week. According to some commonly used calendars, however, especially in the United States, Sunday is the first day of the week, so Tuesday is the third day.

Days of the Week

The names of the days of the seven-day 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 in the Roman Empire during the Late Antiquity. In some other languages, the days are named for corresponding deities of the regional culture, beginning with Sunday or Monday.