Fatto generale: 1255 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 1255 is an uninteresting number.
Trivia: 1255 is an unremarkable number.
Data storica: June 8th is the day in 1794 that Robespierre inaugurates the French Revolution's new state religion, the Cult of the Supreme Being, with large organized festivals all across France.