lol. Mathematics is all anti-clockwise, its just that because the screen your drawing to is vertically flipped it ends up differently: It would be an easy mistake to make.
Revolve the x axis towards the y axis, and that is your positive angle or rotation. When your working in 3d, x to y == yaw, y to z == pitch, z to x==roll, so its always positive when moving one along ...xyzxyzxyzxyzxyz... and negative the other way. Just remmember that.