That's fantastic. Hopefully there's a trend towards this with employers as weed becomes more acceptable.
I am self-employed, and while I don't openly encourage my employees to smoke, they all do, and they all know that I know. I just ask them to take it outside or to their car so that people coming in and out of the office don't smell it.
I actually fired an employee a while back for stealing. Pretty big sum of money. When things couldn't be resolved amicably we took him to court where his defense was ....... I was high on the job, which is why I stole money, my boss knew it, therefor I shouldn't be held responsible.