If I'm setting up a new game, I would just say "Ok, this is the time the game is gonna be." My first game I did a "ok, I'm available whenever, but want it to be in GMT evening timezone." and then people signed up with "Yes I can only play Wednesday and Saturday" or "I can't play Saturday at all, but tuesday is perfect" and so on. I had to sort through all that, and then in the end make a call to when the game is anyway. The problem then was telling those players that couldn't make the time that it didn't work. So for new games: Just set a time. If you have a few players already: Contact them, maybe in a groupchat on skype or PM them, and have them input their available times. Then see if you find one that fits all. Or propose a few times "Ok, I can either play Sat 7 pm, Mon-Wed 6pm or Fri at 5pm, which of those could you make and which not?" But if you then search for new players, have that done already and post a definite date in the forum.