month end closing

month end closing

1) May i know how to define an accounting period in zoho? I did not see the configuration in zoho books. Generally we close accounts on a date earlier than month end. So our accounting period is, for instance, June 26-July 24. How can i define each accounting period in zoho books?
2) at month end, will zoho books be able to re-valuate all account balance denominated in foreign currency?
3) For each custom field in dropbox format, is there a limit on the value I can input?

Thank you
Robin