Divide the 7 1-day worlds up so that each start about 6 days after the other. That way you'll have one new world starting each week. If a new owner misses the start date of a new world, no worries. Another will start up soon. Just like if you miss the subway you know another will be by shortly, not in another hour. Do the same with the 2-day worlds. Start those three worlds at about 10 days apart. Don't know if I did the math right, I just divided the number of worlds by the number of days in a complete season. (just guessing at 45 days and 30 days respectively to complete a season). Spreading out all worlds is the key, not just a few. And never, never never, postpone a world due to Thanksgiving, Christmas, Arbor Day or Labor Day.