1-2 Times a Week
Think back to that awkward moment in school when they started talking about puberty and how you're gonna have to shower more. Remember how they said your body will start to secret oils and stink as your hormones kick in? Yeah, your baby is WAY far away from puberty so the need to bathe every day is quite a few years off.
The parts that get really dirty on a baby are their butts, which get cleaned at every diaper change, and their faces, which gets wiped off pretty frequently. They don't really get dirty otherwise. Baths are more for bonding and working out that annoying lint that collects between their fingers and toes. If your little one gets cradle cap gently scrubbing hair/scalp a few times a week is important, but too much can lead to dry irritated skin. Who wants that for their little one?