Bad days are interesting because they can come, literally, from nowhere. I sometimes feel like my ability to have a bad day should be taught in school: it's of mythical proportions. I wake up and I have a migraine, my nose is stuffy, I got up too late and I have 1,000 things to do which require me in 500 places, and I NEED to get them all done today (probably because I procrastinated for half of the week, but I digress).
I haven't quite found the cure for the bad day.
They ruin your plans, and change the complexity of your day. Even when you successfully accomplish your goals on a shitty day, the day still sucks.
It's Not About the Cure
I know many dedicated and more disciplined people than I who also haven't found the cure, but like American medicine, have become comfortable with suppressing one.
Maybe the cure is in your routine. Running for an hour every day clears the head and allows time for focus. Maybe for someone else, it's weightlifting. Maybe it's cooking or cleaning, or any sort of organizational task.
For an artist, a lot of times there aren't any other options when we're having a wretched day.
We either work or we don't. And not working is not an option.
So, we work angrily, and that is better than putting it off until the next day. Your "real work" (art) has to become a part of your daily routine. The same way that brushing your teeth, applying lip balm and drinking water when you're thirsty is automatic.
I'm not creating the next "Great American Novel" every day, especially not on my bad days.
But maybe tomorrow I will… And tomorrow can only be better.