Setting the timer?

I have a Sundance Tango hot tub that I got over the summer. There is a timer on it, like an analog auto light timer for a lamp. I am assuming it is used to automatically run the pumps to keep the water moving a bit and to heat the water so it doesn't freeze in the winter.
I am located in Massachusetts, so cold is an issue.

I wanted to know if:
A) I understand the point of the timer correctly.
B) How often the tub should come on per day and for how long. (I don't want to waste electricity, nor do I want the tub to freeze...)


Thanks.