The sign for "Sunday" has several popular
Hold your hands up about head high and then move your right hand in a
clockwise circle and your left hand in a counterclockwise circle as if you
were washing a window with both hands:
SUNDAY: (Other version)
Hold your hands up, palms forward, "5 handshapes" in front of and to the
sides of your head. Bring them down to your torso area. The
movement from top to bottom forms a backwards
(Yet another version.)
This version starts at your torso, arcs in a bit
(back towards your chest) and out again at about head height.
In this version of the sign, when you bring the hands down you bring them
straight down without arching them in toward your body.
Some people do the sign "WONDERFUL/great" to mean Sunday. I
do not recommend doing that.
Why choose to sign in a confusing manner? There is no need, we already have
other versions that work well and do not conflict with "wonderful."