Working f/t in the NHS, and we usually have to give at least a months notice for A/L - we can sometimes get away with less notice if no-one else has asked for the day off and if the service allows, but normally a month. DH has client meetings from now until about 2067, and again has to give a lot of notice for A/L.
Over the years, I've had invitations home from school with around a weeks notice to come in and view the DCs artwork/attend a charity coffee morning/go and see the class show etc etc. I've just had another one in on a beautiful handmade invitation from DC3 with a weeks notice - he was desperate for me to attend, and very fortunately I've been able to reschedule something and have put in for A/L.
Why do schools often give such little notice, esp. when they've been working on the arr/show/etc for weeks? Not trying to start a fight, just trying to get my head around this.