What is happy b.day?

Happy Birthday is a common phrase used to wish someone a happy birthday on their special day. It is typically celebrated annually and marks the day of someone's birth. Birthday celebrations often include gatherings with friends and family, gift giving, and special activities or treats. Some common traditions include lighting candles on a cake and singing "Happy Birthday," blowing out the candles and making a wish, and opening presents. The date of someone's birthday is often considered a personal and special holiday and is celebrated in many different ways around the world.