HARTFORD, Conn. — Happy Birthday, Spongebob!
While the show first aired on May 1st, 1999, the actual character's birthday is July 14th, 1986!
His birthday is displayed on his license which makes its first appearance in the episode "Sleepy Time" back in 2000, according to the fandom wiki.
The voice actor for Spongebob, Tom Kenny, also celebrated his birthday on July 13th!
Kenny has voiced several characters on the show since 1999, including Spongebob, Gary the Snail, and the French narrator.
According to an article by the Washington Post, one of the largest sea sponges discovered may be thousands of years old, so Spongebob has quite a ways to go.