How can I program my garden hose timer?

I have a garden hose timer with the lid (with instructions of how to program) lost. It is round, gray with a white face with 16 buttons on the face. the buttons have yellow numbers and orange days of the week. It has a "Skip day" , "Water Once" , "Set", ON, TIME DAY, AND OFF/CANC buttons. The buttons are arranged in 4 rows with 4 buttons. There is no indication of what brand this hose timer is anywhere inside or outside. I suspect all of that information is on the lid.It runs on 2 AA batteries