Booster Gold (Michael Jon Carter) is a fictional superhero appearing in American comic books published by DC Comics. Created by Dan Jurgens, the character first appeared in "Booster Gold" #1 (February 1986) and has been a member of the Justice League.
Booster Gold's first appearance was 33 years ago.
In the text, Booster Gold #1 was published in February 1986. Since that was his first appearance, he did indeed appear 33 years ago. The system probably tripped on the different way of phrasing time.