For myself... When I'm doing bad, most days are bad. I'll have a good moment here or there. <grin> I've started recording them! (So I don't forget and can look back at them, instead of thinking is been straight awful). On average I'm having about 10-15 good minutes once every 2 or 3 weeks, lately. Have had 2 'good couple hours' this year. And 1 good day. Bliss.
When I'm doing well, most of my days are good. I might have a couple bad nightmares a year. A couple panic attack here and there. A month of insomnia. A bad day, or a bad week.
When I'm shifting in between doing badly & doing well? Moving up or down? My schedule looks a lot more like that. Good day, bad day.
The transitions are frustrating... Whether I'm getting better or worse... Because of the split. When I'm going down, I can see myself becoming less and less functional, and it's infuriating. When I'm going up, I have enough good days to actually start to become functional again... But the bad days slow things down, and make me question whether I'm actually ever going to be functional again. Which is infuriating.