Sadly PG the logic of your argument will have no impact on the system, so don't even waste the energy on it mate!
The problem with 24hrs notice is the usual vagaries of aviation!
In practice its no biggie: give them much more than 24hrs notice if you think you might be going, then call them nearer the time to tell them the time/date has changed and you have whatever flexibility you require. That way, their needs are met, and you get to do what you want when you want. And it you cancel, just tell them - no drama.
Andy
