Well, i dont think it's possible to figure out what makes a good/bad day cause than there wouldn't really be bad days...
but my take on it is that it's based on chance.
i think good days build from confidence from opportunities given by chance. During the night maybe your body found a wonderful position to rest in and that gives you confidence that morning. than you get a chance to use that confidence in school when luck appears in the form of a HB giving you a smile or you making a great joke that just pops into your head. and it goes on and on. your confidence rises with each lucky event giving you more confidence and more opportunities that day.
than on a bad day, you wake up feeling tired or achy. from bad sleeping position or not enough sleep. you feel a little tired, then your vibe gives HBs reason to reject you which makes you feel more down/tired, spiraling your day down into a terrible day.
i say make your own chance and build your own confidence by choice. go talk to some HB you know you have good rapport with, get some confidence boost and take your day from there.
sorry if its choppy, it's late where i am
also agree with music and little things to make your day better
enjoy the little things in life haha
