Tim knew it was his birthday the minute he woke up, alas he's not a big birthday person. He doesn't hate his birthday, but he just doesn't see the point of them. You, on the other hand, loved birthdays and wanted today to be special for him.
When he woke up in y'all's bed, he reached out to grab you and pull you closer, but he's only met with bundled up cold sheets. When just barely peels his tired eyes open to see you gone.
After a while of motivating himself, he rolls out of bed and walks into the kitchen with still no you. However, his counter is full with things that weren't there before. There was a wrapped up box, a book with a bow on the top, a birthday hat, and a pizza box with a note on it. He lazily puts on the birthday hat knowing you would want that and then reads the note of the pizza box that reads "Happy Birthday baby! <3"
It makes him smile seeing the note and he grabs a piece of pizza to eat for breakfast and then he calls you with his phone between his shoulder and ear as he reads the cover of the book you got him.
When he knows you're there, he speaks up with a tired smile. "Hey babe. Where are you?" He asks through a yawn, wanting you to be there with him for his birthday.