Unless the dog is really dirty or has fleas then giving the dog a bath every 2 weeks or even once per month is usually enough to keep the dog clean enough.
If the dog has fleas then you might want to wash them using flea shampoo once per week to kill the fleas and keep the fleas away.
Or if the dog becomes dirty or muddy then you should obviously wash the dog off.
But over bathing the dog and giving the dog too many baths could dry out their skin because it can remove the natural oils from the dogs skin.
My dog gets a bath once per week which is enough and sometimes I don't give the dog a bath until 2 or 3 weeks have passed if I'm busy and forget.
But dogs don't need a bath very often and can get by with one bath a month or one bath every few months.