Wednesday is the day of the week between Tuesday and Thursday. The astrological sign of the planet Mercury represents Wednesday, which was dies mercurii to the Romans. In English, this became Woden's Day, since the Roman god Mercury was identified with Woden in northern Europe.
When Sunday is taken as the first of the week, Wednesday is the day in the middle of the week; correspondingly the German word for Wednesday is Mittwoch (middle of the week). Also it is in the middle of a working week from Monday through Friday. However, see also Thursday and ISO 8601.
In the popular rhyme, "Wednesday's Child is full of woe".