Harry didn't know his birthday. He knew Dudley's birthday though. It was the twenty-third of June. Aunt Petunia made it a very important day. Harry had to wake up extra early on Dudley's birthday to make a cake and to clean.
There was so much to clean. First the kitchen after making a mess while baking Dudley's favorite cake (double chocolate with buttercream frosting). Next the dining room so all of Dudley's friends and family could eat like royalty. Then the parlor so company could be brought in properly. After, the bathrooms were made spotless. Finally, Harry swept the stairs out front so Number 4 Privet Drive would be pristine to the outside world.
After that whole ordeal, Harry was sent to the cupboard with a sliver of cheese rind and a bit of bread. Harry was thankful to be left alone. Harry hoped he'd get the chance to try some of the cake. He'd done his very best work so far.
Harry wondered when he'd have a birthday. He hoped he'd get a hug. Those seemed nice when Dudley got them from Aunt Petunia and Uncle Vernon. A cake would be nice too. Maybe something sweet with caramel? If it was Harry's birthday he wouldn't make people clean. He'd just want people to be happy. And no one would yell or shout and he wouldn't be called boy. That would be a nice day.
Unfortunately, Harry's dreams about his own ideal birthday were smashed when he was called out of the cupboard to play Musical Statues with the rest of Dudley's party members. Harry liked musical statues. It was nice to dance around to music and he was pretty good at freezing. All the other children kept falling over though, leaving Dudley and Harry as the last two playing the game. In the fun, Harry had forgotten the rules involving Dudley. Dudley was the precious one, he had to win. Aunt Marge whacked his shins with her walking stick until he fell over.
Harry was sent back to the cupboard for almost out-showing Dudley. He didn't get cake.