Save as provided in sections 66 and 78, an order fixing, altering or commuting the rent of a holding on an application under this Act may, as the officer making the order thinks fit, take effect from the commencement of the agricultural year next following the date of the application, or from any subsequent day, or, if it is made on the ground of increase, diminution or deterioration of the holding, from the date of that increase, diminution or deterioration, or from any subsequent day.