many people think of tuesday as the third day of the week but according to international standard ISO, it is the second day of the week!
So according to the International standard ISO, they week starts on Monday?
yes. also the name tuesday derives from the old english "tiwesdæg" and that means "tiw's day"
Do all the names of the days of the week derive from old english?
im not sure about other days  but youre probably wondering what tiw is, tiws day was the day of tiw or tyr. tiw is the god of single combat, victory and heoric glory in norse mythology.
Was tyr also a god in norse mythology?
, 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 'Mars day' from 火星 (kasei
Tuesday
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 and so 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 and so Tuesday is the third day of the week. The English name is derived from Old English "Tiwesdæg" and Middle English "Tewesday," meaning "Tīw's Day", the