When & how was it decided that a rugby game should last for 80 mins instead of 90 as in football?

Question

When & how was it decided that a rugby game should last for 80 mins instead of 90 as in football?

Answer 1

Have not researched when or how, but would presume the reason for how was decided because it is a fierce physical contact sport and this would take a much higher toll on the body than football.

Answer 2

cos rugby is a girl's game