I wonder how the people saying "just set an alarm and phone at 8 am" would feel if the phone line opening time changed to 3 am - right in the middle of their own normal sleeping time?
Because when my diurnal rhytm was wrecked and I couldn't get to sleep before 5 am I found it completely impossible to set an alarm and be awake and coherent enough at that hour to explain why I needed an appointment.
Several times I did set the alarm, got up, waiting an hour on the phone to a recorded message saying they were very busy and would be with me shortly, and then on the stroke of 9 the recorded voice would say "The line is now closing. All the appointments have gone. Please call again at 8 am tomorrow if you need to book an appointment" I went 18 months without being able to book an appointment for what turned out to be a serious problem that was made worse by the delay.
Since I started pandering to my gut microbiome I now fall asleep by 11 pm so it is easy to be up at 8 am, sipping coffee and listening to the recorded voice telling me that they are busy and I am in the queue. I can also be dressed and in the surgery half an hour later if I am lucky enough to get through and they find a slot for me.
However, when I lay awake, tossing, turning, twitching and cursing until 5 am, asking me to be awake and ready to spend an hour on the phone and then leave for a morning appointment was EXACTLY the same as if they now changed the phone opening time to 3 am and expected me to turn up at the surgery by 4 am. It might be possible with enormous effort, but it wouldn't be easy and I'd be too exhausted to think straight and explain why I was there.
It really is unfair to discriminate against people who are unable to function in the morning. Many of them will be suffering from debilitating mental and physical illnesses. There's absolutely no reason at all why half the weeks appointments can't be reserved for the afternoons, with the phone line opening at 12.