Where did we get our idea for a "week"?

Question

The "day" comes from one earth rotation

The "month" comes from earth and moon

The "year" from earth and sun

So where did the "week" come from?

First person to answer correctly, gets 10 points.

Answer 1

IT IS A BIBLICAL PRINCIPAL. GEN. 1&2 YOU HAVE SIX DAY OF CREATION AND THE SEVENTH DAY OF REST WOULD BE A WEEK.
MENTIONED AGAIN IN EX. 20:8-10.

Answer 2

The greek same for 12 months