For me at the moment a good day is a day without a migraine headache, currently that is three days out of five, in a fairly regular 2day/3day cycle.
On the migraine free good days I don't need to close my eyes and pretend to be a jellyfish without a brain every few minutes to prevent pain building up in my head, as I must do today to write this. On a good day I am still housebound and need to be very careful with how much activity I do or I will crash and get PEM 24 hours later, (which now includes a pounding headache as well as heart arrhythmia, IBS, viral recurrence, adrenal episodes, irresistable sleepiness, cognitive dysfunction including brain fog, emotional lability like euphoria and irritability, if it gets worse then cognitive disruption involving hallucination and paranoia, rigors, etc).
To avoid all that I have to rest most of the time and if I am careful and lucky I can pace my way through light activity such as hoovering a room, say one room in the morning and one in the afternoon and then rest for the remainder of the day. Or clipping a few metres of lawn but not both, or cooking for the freezer to make life easier on worse days but I can't do that as well as hoover on a good day, or it will become a bad day, if you see what I mean. I usually pick one task per day and try to get it done with careful pacing. If I do too much it takes 3 days to a week of rest to recover to my rested state.
I can do a fraction of what I used to be able to do but at least I am not in constant pain. It has taken the best part of an hour to write this, I must stop to get to sleep on time or it will mess up my day tomorrow.