No matter what you or the weather or the sun might tell me, yesterday was the first day of summer.
I realize that feeling has more to do with societal conditioning than anything else, most of us spent 12-16 or more years in schools where everything pointed to summer vacations that started about now.
So, why fight it?! Why not go with what feels natural? As long as you're not hurting anyone else why not go with the feeling or flow that feels right to you?