One important argument I always use is (I also work 30h/w): "You get my most productive 30 hours per week. You know those hours where you somehow don't feel pr

One important argument I always use is (I also work 30h/w): "You get my most productive 30 hours per week. You know those hours where you somehow don't feel productive and you end up doing stuff that wasn't really worth it ? I don't work those hours."