I have a small request to make of you all.
If we have an appointment, and you can't make it or you're going to be late, please let me know, preferably ahead of time. If this appointment involves me going somewhere to meet you, ideally, let me know early enough that I'm not going to make a journey for no reason.
On a similar note, if you've promised to do something for me by a certain time and you're not going to be able to do it, I'd appreciate it if you'd tell me, rather than just leave me wondering what's going on. It'd make my life so much easier.