G-SPOT, I found that on my CPL my training buddy and I were often the only students that our instructor had and so we had the aircraft allocated to us all that day, therefore when the weather was bad for example early in the morning, we would simply push the lessons back to the next slot. That was my experience but I guess it would be down to how many other students your instructor had booked in that day, if it was only you then you would simply take the next available slot that day. It was never a problem for me. I think your find that your instructor wants you to fly as much as you do and it’s in their interest to try and get your lesson in if possible.