Period End under the Maintenance menu, however I must warn you that it does not work the same way period end does in other modules. BankRec does not respect the 'retain history for xxx days' set in the company profile. All transactions are cleared to the period end date set so, for example, if you wanted to keep the last 365 you must set the period end date back that amount (whereas AP & AR you can use the true period end date and the date to purge history up to is calculated based upon the number of days to keep history set in their comapny profiles).
Something the develop will hopefully fix.