How to turn off hourly chime on digital watch

Question

I have a TIMEX watch with 5 buttons. The top left button says light, the bottom left says mode,the top right says st./stop, there's a bottom right but I don't know what it says, and there's a button on the miidle bottom that also says light. It is purple and says WR 50M on the strap. I am trying to figure out how to turn off the hourly beeping on it. How can I do it?