What should I do about a neighbour waking me up with their lawn mowing?

Ever since the weather has warmed up and the gr has grown, I have been woken up every weekend morning at around 9 am by the extremely loud lawnmower of one of my neighbours. I live in Ontario. Is there a law about how early one can mow the lawn here or anything like that? I feel like if there was something legally wrong with what they were doing, then there would be more of a chance of me growing the to go talk to them and/or them taking me seriously. I would very much like to put a stop to this.