The sign for "week" has a couple of variations. The basic
sign for "week" is
made by forming your dominant hand into an index-finger handshape and moving
your hand forward over the palm of your non-dominant hand.
"One week has how many days?"
The sign WEEK can also be done with the left
hand (or non-dominant hand) in an "index finger" handshape, palm facing right. The
right hand slides outward over the top/side of the left hand and index finger.
If you are holding a drink or a sandwich in your left hand you can even do this sign without
the left hand! (Like most signs actually).
See "week (advanced)"