How to work in future accounting periods
Also described as, "How to work in the next year"
There is no need to change the accounting period to create future transactions. No matter what the current accounting period is, you may simply create transactions dated in future periods.
You may even date the transactions into the next fiscal year.
All reports will be based on transactions that fall within the chosen time-frame, so future transactions will not affect reports unless you extend the date range to include them.