National Regular Average Ordinary Day by Lisa Katzenberger
He even rates them on a scale of 1 to 10. But when he wakes up one morning to discover there isn't any holiday, he realises he'll have to take matters into his own hands and make up his own! That's easier said than done, though, and nothing seems to go right - until Peter realises that even a regular, average, ordinary day can be something worth celebrating.