Ten years ago I was a homeseer user, and I seem to recollect it had the notion of some randomness that could be specified around a particular start time. You could easily specify to turn on a light at, say, sunset plus or minus 20 minutes. That is to say, each time it would turn on randomy in that range: sunset + 1 minute, sunset - 6 minutes, sunset + 17 minutes, etc. This way, it helped give the illusion of not being on a timer per se.
Does Vera have this, or does it require some luup hacking to get there? I’d rather not get into that–at least not yet. I have a Vera 1, and so far I don’t see it. Maybe it’s in the software for Vera 2/3?