The times depend on which resort. Some of the resorts are on a Mon,Wed,Fri schedule, and others are on a Tues, Thurs, Sat schedule. The Contemporary, where we stayed in January is on the Tues, Thurs, Sat schedule, and the characters were there about 7:40 in the morning.
Your best bet is when you check in, to get the schedule for your resort. The characters vary, day to day.
<table width="350" border="0" bgcolor="#996433"><tr bgcolor="#F0A268"><td width="125" bgcolor="#FFCCFF"><div align="center"><img src="http://www.geraldfield.com/nadinesplace/muppetquiz/fozzie.jpg" width="125" height="108"></div></td><td width="177" bgcolor="#FFCCFF"><p align="center"><b><font size="3" color="#612203">You are Fozzie!</font></b><font color="#612203"><br><font size="2">Wokka Wokka! You love to make lame jokes. Your sense of humor might be a bit off, but you're a great friend and can always be counted on.</font></font><font color="#950000"><font size="2">.</font></font></p></td></tr><tr bgcolor="#996433"><td colspan="2"><div align="center"><font size="1"><b><a href="http://www.geraldfield.com/cgi-bin/unofficial/quizzes/sfesurvey.cgi?whatmuppetareyou" target="_blank"><font color="#FF99FF">Take the <i>What Muppet Are You?</i> Quiz!</font></a></b></font></div></td></tr></table>