Indeed, 8:30p is no different from 2p or 10a for the act.
It's most likely a matter of happenstance. It happened to be the warmest time of the day (even though it was evening). Maybe the thinking was someone was home to help them find the valuables, maybe not.
> 8:30p seems like a dumb time for a home robbery.
The assertion that there is some optimization for some specific imagined motivation, is literal fantasy.
Fewer crimes are committed when the weather is bad since criminals avoid going out like everyone else.
It's a fantasy that strongly correlates with facts. Home robberies are not evenly committed throughout the day.