Ironically, more fights happen on each other’s birthdays because they both on insist on spoiling the other rotten, even the one having the birthday.
While France demands for England to sit down for once in his life and celebrate, England is always trying to insist that “all these festivities are not needed, can’t we just go somewhere fancy tonight and make it a done deal” (in which France in reply just asks England whether he wants fruits on his birthday pastry).
On the other hand, even before France wakes up, England has all these gifts prepared to give and a full schedule for the day. There’s a lot of, “Well where do you want to go?” back-and-forth between the two during the day, and at the end of the day there’s a scuffle about the cake England baked (we’re still not sure if France still forgets England can cook sweets correctly or if he’s just making it a tradition at this point).
By the end of the day, however, they both had tons of fun and they wouldn’t replace this day for anything else.