many happy returns
Also, many happy returns of the day. Happy birthday and many more of them, as in I came by to wish you many happy returns. This expression was first recorded in a letter of 1779 where the writer meant "Happy New Year," but the present meaning has persisted since the second half of the 1800s.
Dictionary.com presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.