Quick Answer: Wednesday is the day of the week in between Tuesday and Thursday. According to international standard ISO 8601, it is the third day of the week. However, in countries that adopt the traditional "Sunday first" convention, where Sunday is the first day of the week, it is the fourth day of the week. In English, the name is derived from Old English Wōdnesdæg and Middle English Wednesdei, 'day of Woden', reflecting the religion practiced by the Anglo-Saxons, the English equivalent to the Norse god Odin. In many Romance languages, such as the French mercredi, Spanish miércoles or Italian mercoledì, the day's name is a calque of Latin dies Mercurii 'day of Mercury'. Wednesday is in the middle of the common Western five-day workweek that starts on Monday and finishes on Friday.