In Hebrew, Arabic, and Persian, the word ‘Sunday’ means ‘first’.
The Greek name for Sunday is Κυριακή (Kyriake) which means “Lord’s Day”.
Sunday was the day of the Sun god in Roman culture.
If a month begins on a Sunday it always has a ‘Friday the 13th’ in it.
There are countries like Bahrain and Bangladesh, where the work week begins on Sunday. This is true of all countries that follow the Islamic calendar. In these countries, the weekend is on Friday and Saturday, making Sunday the first working day of the week.