It depends how often you change your clothes, or (if you're a girl) you're on your period, (if so, probably every day) but i suggest at least once every couple of days.
daily
every day or night
Every day.
Dogs usually don't take showers. When their human bathes them, the human decides how long the dog should be in the bath or shower.
ONE
At least every other day.
everyday when you shower right after you put shampoo in it
every day
Every other day or every day
Every day or every two days.
at least every other day
If the shower curtain is in bad shape then it need to get replaced ASAP. Shower curtains are very cheap. If people go somewhere like a dollar store they can get them for one dollar.