Ground coffee begins oxidizing within 2 minutes. It's arguable "fresh" for 15 minutes (conventional wisdom, via "the rule of 15's" Fresh = 15 months for green, 15 days for roasted, 15 minutes for ground).There shouldn't be much harm in grinding a few days worth at a time should there? I am eagarly awaiting my new grinder so I don't have much experience. I wake up a half hour earlier than my lady and would hate to wake her up every morning.
I lean toward 15 second for ground. Your goal should be to take your ground coffee straight from the grinder and into the brewing device and begin applying your bloom water immediately.