>Recently I've read conflicting accounts:
>
>http://www.pantheon.org/miscellaneous/origin_days.html

Restricted to a few languages of the West, ignoring the whole rest of the world.

>http://www.webexhibits.org/calendars/week.html

Better... a bit, as it includes Russian. It also assumes that non-believers never rest (probably in solidarity with the commissars, who would lead you to believe you can recognize the enemy by red eyes, because "the enemy never sleeps").

>http://www.ac.wwu.edu/~stephan/Astronomy/7day.html

Somewhat better. I still have no clue as to how days of the week are named in Asian, African and American American languages. World is larger than that.

BTW, in Slavic languages and Hungarian (which seems to have borrowed Wednesday to Saturday and the recipe for Tuesday), Tuesday is derived from 2^nd, Thursday is "four-er", Friday is "five-er", which makes Thursday the effective middle day of the week. But the word for Wednesday, sreda-sereda-szerda actually means "middle". Go figure.