There’s no such thing. If you get up and your head looks like a military compound, sort it out.
Wash it, dry it properly, maybe comb, brush it or put some product in it and once that’s done you can get over yourself and get on with your day.
A bad hair day is a lame excuse for ugliness. Bad hair is the human equivalent of a poorly chosen garnish. If you have a face like a climbing wall, a decent hairstyle will not put you in the Brangelina league. Ugly people say ‘Oh deary me, I’m having such a bad hair day’ but no-one has the gumption to say, ‘No, it’s fine, it’s just you’re butt-ugly.’