Tuesday is a day of the week occurring after Monday and before Wednesday. According to some commonly used calendars (esp. in the US), it is the third day of the week. According to international standard ISO 8601, however, it is the second day of the week. The English name is derived from Old English Tiwesdæg and Middle English Tewesday, meaning "Tīw's Day", the day of Tiw or Týr, the god of single combat, victory and heroic glory in Norse mythology. Tiw was equated with Mars in the interpretatio germanica, and the name of the day is a translation of Latin dies Martis.
The name Tuesday derives from the Old English "Tiwesdæg" and literally means "Tiw's Day". Tiw is the Old English form of the Proto-Germanic god *Tîwaz, or Týr in Norse, a god of war and law. *Tîwaz derives from the Proto-Indo-European base *dei-, *deyā-, *dīdyā-, meaning 'to shine', whence comes also such words as "deity".
The Latin name dies Martis ("day of Mars") is equivalent to the Greek ἡμέρα Ἄρεως. In most languages with Latin origins (Italian, French, Spanish, Catalan, Romanian, Galician, Sardinian, Corsican, but not Portuguese), the day is named after Mars, the Ancient Greek Ares Ἄρης .
In some Slavic languages the word Tuesday originated from Old Church Slavonic word въторъ meaning "the second". Bulgarian and Russian "Вторник" (Vtornik) (Serbian:уторак (utorak)) is derived from the Bulgarian and Russian adjective for 'Second' - "Втори" (Vtori) or "Второй" (Vtoroi).
In Japanese, the word Tuesday is 火曜日(ka youbi), meaning 'fire day' and is associated with 火星 (kasei): Mars (the planet), literally meaning "fire star". Similarly, in Korean the word Tuesday is 화요일 (hwa yo il), also meaning fire day.
In the Indo-Aryan languages Pali and Sanskrit the name of the day is taken from Angaraka ('one who is red in colour') a style (manner of address) for Mangal, the god of war, and for Mars, the red planet.
In the Eastern Orthodox Church, Tuesdays are dedicated to Saint John the Baptist. The Octoechos contains hymns on this theme, arranged in an eight-week cycle, that are chanted on Tuesdays throughout the year. At the end of Divine Services on Tuesday, the dismissal begins with the words: "May Christ our True God, through the intercessions of his most-pure Mother, of the honorable and glorious Prophet, Forerunner and Baptist John…"