I went to bed at 3pm yesterday afternoon for a "nap" after coming home from work unwell, really feeling dreadful.
I've just woken up! We're supposed to phone in by 7:30. I'll have to call an apologise, but it's occurred to me that actually, if you live alone (so no one to wake you) this would be common, if you are indeed quite ill?
I've only recently lived alone after 3 decades of a DH and DC in the house, so little chance of sleeping in no matter how ill you are.