The MK morning show is not done on Magic Mornings. So it is Monday, Tuesday, Wednesday, Friday and Saturday at 8:50am (8:50 is the scheduled time but if the crowd at the turnstiles is very large they will start it earlier but not by much...the train isn't avalaible to pick the characters up until 8:30 at the earliest).
As Jimmiej mentioned the Trains are not avalible on these days to guests until about 9:05. The train that is used for the show is modified to allow the characters to step off on the left side, so it is not used in daily service. Once the show is over the "Show train" is returned to the roundhouse and the first train in service will be waiting just outside Main Street Station, once all the entertainment and techs are clear the train will be cleard to proceed and start daily service.