RWCS ... After 4pm when the mothers start bringing the kids back from school ... 5pm onwards is your prime time though. I still do daytime knocking (10-2) but evening is obviously better.
SHC ... You are always going to get the occasional one who may mind,just put it out of your head, never had anyone rude though. The good thing with the dark nights is that you can tell who is in as the lights will be on. The only issues I have ever experienced knocking in the dark is if I'm working a low lighten street, not that they mind but some householders are a little suspicious. Don't let it stop you knocking though.