Oh defo!!!
Housing Associations and social housing landlords in general will just dish out appointments to tenants, and never check to see if it's convenient!!! Electrical checks that take 3 hours, gas safety checks that take an hour, remedial work that's done every 5 years (like outdoor painting and maintenance,) that can take several days, and 5 year general maintenance check-ups, that can take 2 hours.
My friend had a letter with an appointment for the 'Housing Inspector' to come and do a 5-year maintenance check up, and it was 10th May. (It was gonna last 2 hours.) The Wednesday of the following week. The letter said to ring and re-arrange if it was not convenient.
She rang them and said she is at work and she and will have to re-arrange it. She said 'I am off for 3 days the week after next, so they can come then.' (Would have been about 17-19 May.) The woman said 'oh no sorry, Jeff our Inspector only does your area on the second week of each month, so he won't be able to come back til week commencing 8th June.'
So my friend said 'well we will arrange a date for that week then. Give me a date and I will book off the morning... I will struggle to book off next Wednesday morning though... Bit short notice... and I have a meeting' The woman said 'oh no sorry, Jeff doesn't send his appoinments out til 1-2 weeks before, so for the second week in June, the letters will come out around 30th May. We will send you a date for the second week in June then, but we can't guarantee the date.' My friend said 'but there's no guarantee I won't be at work again!' The woman said 'well we can just send another date for July, and if that's no good just keep going til we catch you in.' 
My friend said 'ya know what, sod it, just leave it, I will book the morning off on 10th May!' They made it so hard for her to re-arrange it, and she knows if she had let it go on and on, they would have accused her of contravening the terms of her tenancy by 'not letting them in...' and probably put her on some kind of warning... 🙄 So she had to use holiday leave, and re-arrange a meeting.
Same happened to someone I know with her gas safety check. They kept sending out letters with dates on for her to have her yearly safety check, and just assumed that she would be in. She is a really busy, frazzled working single mum, and she missed them 3 times, and they send her a letter threatening to end her tenancy and evict her!
Honestly, they assume everyone in social housing doesn't work!!! Not only that, but they assume that everyone has fuck-all to do except sit in and wait for them! It's so stupid. And as has been said, some people actually cannot take calls randomly at any time of the day, and have to do it on their break or lunchtime. Not everyone is allowed to take calls in works time!
And the NHS just sending out random appointments to people without checking first if it's OK is just as stupid. People can easily miss the letters and then get taken off 'the list.' (And there is the assumption that people can just sit by the phone all day until they can be bothered to phone!!!)
And as has been said, it makes you wonder how many 'did not attends' and 'missed appointments' actually WERE what they said, or were they cases of them sending random appointments out assuming people can make it, (and people not getting the letters, or not being able to make it,) or 2pm phone appointments that actually ended up being at 3.30pm resulting in the person being unable to take the call/missing it?!
I remember a time (some 10 years ago) when they would send letters out to people with a username and a code to get into an appointments page online, and you could select an appointment. WTF happened to this system?!