Backdate Transactions to a Closed Period
Backdating a transaction means entering a date before the current date. For example, today is July 1, 2021 and I enter an invoice with the date June 1, 2021. That invoice is backdated.
A cost recalculation happens when you backdate a transaction to a date within a closed period and then later reopen that period.
Best Practice
If you backdate a transaction to a date within a closed period, you should first open the closed period before saving the backdated transaction.