We celebrate each employee's brithday. I let employees know that its the employee's Birthday by wishing the employee, on behalf of everyone on the intranet. We assemble after lunch & present the person a bunch of flowers & cut a cake. This is all on the company's expense.
In my previous Company, since it was a hotel, the number of staff was very high. We used to cut the cake on the last Saturday of the month. The cake was cut by the youngest 2 employees. Also, during lunch, it was a grand lunch with executives serving the lunch instead of the chefs. For the executives, since it was a smaller number, we celebrated Birthdays on the day of the Birthday itself. A bouquet was presented and cake cut in the executive dining hall.