you should always have them on
Why?
There are several tens of millions of reasons for this ~ among them are the elderly for whom any increase in the level of glare is an unmitigated disaster. Whether they are passengers, pedestrians, or even drivers, any reduction in their visual accuity is not advisable.
Even for folks who have no vision problems, there's always that rear-view mirror. Really nothing quite like an SUV behind you with his highbeams on ~ that's the OTHER disaster ~ too many people don't know how to switch to their low beams. Last thing we want to do is advise them to turn on their headlights.
I'm not Canadian.