The PRORATE function does not exist in Excel (to my knowledge, reinventing it was cumbersome).
We use it to spread budget accross time.
Indeed, with the right columns and rows, Yearly (can be quarterly, monthly or whatever) budgets adjust as the dates change.
Then dedicated boxes consolidate to overview at a glimpse.
PRORATE is straight forward to use with 5 logical parameters. See http://help.smartsheet.com/customer/portal/articles/775363-using-formulas#advanced
I find it especially useful when I make up a new project plan, with a lot of date changes at this stage => Budget is always aligned :-)
Would you like me to issue a short template?