Well I think this prevents people from being too active to win the guild challenges. You can always increase the accumalated days limit (really useful when your out for a long time like sleeping). I think its 5 when you haven't bought any starter kits. 7 when you played the game a while ago on FB. 9 when you buy Iron starter kit. 11 when you buy Steel starter kit. And 14 when you buy Mithril starter kit. 14 is limit so that means you can only purchase one starter kit.
