Need Clarification about Stay in USA with H1B


I’d like to know +ve and -ve on below scenario.

  1. Can i travel to canada for 2days with US visa?
  2. Visiting canada on weekends won’t counted in H1B 6Years stay. Am I correct? If yes, then
    if i go canada on every weekends, then i’d save 2days per week from H1B 6Years stay and the same in USA?
    please advise me.