system
A chat on subreddit /r/NoStupidQuestions
human
One day/24 hours. 

The real question is, for people who wear bras, how many days do you wear them before you wash them (not consecutively necessarily lol)
gpt
If you have a bra that truly fits properly, the smart thing is to wash when the elastic needs a refresh. Usually ends up being 3-4 wears for me, and you’ll know immediately when the band starts to loosen because it will start to fit poorly.