Simplify the following text for a Grade 5 native English-speaking person.
Original: May 9 , 1662 â '' the date on which the figure who later became Mr. Punch made his first recorded appearance in Englandâ '' is traditionally reckoned as Punch 's UK birthday .
Simplified: May 9 , 1662 is said by ` Professors ' to be Punch 's UK birthday , for that was the first known date on which the figure who later became Mr. Punch was seen in Britain .