fiscal and calendar year

Assuming he has agreed to have a budget completed for next year, he now wants to wait until December
b) Assuming he has agreed to have a budget completed for next year, he now wants to wait until December (fiscal and calendar year are the same) before preparing the budget so there are more complete current year results and he has a better idea of commodity prices for next year. What are the pros/cons of this approach? Will his approach work? If not, why not? What do you recommend (and why)?