Sorry for being so long in replying... I remember thinking "in a minute" and now it's been two days...
I'm already working on 3 different due dates (for the 3 icontests I mod) that work pretty fine for me, so there's a bit leeway I could give when it comes to days participants prefer... that doesn't mean I'd pick a day that's not going to work for me - more like aligning days that work for both sides.
I guess I'll just try it out to see if it works better with longer time (and add a couple of other perks :D )... at least for as long as the semester runs/keeps me busy.