Heh, yeah, seems to work a bit different for these kinda games though, since most sites that host these things tend to promote them on the actual release day, having things promoted on days where people have time to play them (I.E, the weekend) makes sense. There are people who will see something get released and think "Oh, I'll play that when I get some time", but a lot of those people will forget. Best to target a release day when people who aren't already supporting the game can see the update, and download any play it before they get a chance to forget about it.
Didn't stop me releasing the initial 0.22 version to patrons on a random Tuesday though, since I was already a bit late on it. I figure if someone is already giving me money to make the game, then they probably won't forget about it, so there's no issue. But yeah, for a public release, definitely best to do it when people actually have time to play.