This thread has made me see I should say on form afternoon appointments are best for me. I am not good in mornings, takes me while to get going plus I am not an early rise due to my conditions. I have never done it before, only put dates I can't do, didn't think to put time of day!
It's important to state on your ESA50 the time of day, day of week, or any days or weeks that you are not available for a medical, so that it's on record.
But please don't expect Atos to take a blind bit of notice. See the thread below.