This is the limited date range during which you or your users may generate entries. It should match your open fiscal years accordingly. You can see the current period under Company Settings - Finance Settings - Working Period Start/Working Period End. See below:
Note: Maximum time frame allowed is 2 years.
Open the Accounting Transactions view (Accounting - More - Accounting Transactions) and click New Accounting Transaction.
To move on to the next field: TAB
To save a transaction:
MAC: CMD + RETURN
PC: CTRL + ENTER
Closing a Tax Period
Closing a tax period (see under Accounting ) blocks all accounting entries comprised within the closing:
users can then generate a tax report