Imagino que el query que quieres filtrar por fecha seria el siguiente:
Código PHP:
$orders_query = tep_db_query("select distinct op.products_id from " . TABLE_ORDERS . " o, " . TABLE_ORDERS_PRODUCTS . " op, " . TABLE_PRODUCTS . " p where o.customers_id = '" . (int)$customer_id . "' and o.orders_id = op.orders_id and op.products_id = p.products_id and p.products_status = '1' group by products_id order by o.date_purchased desc limit " . MAX_DISPLAY_PRODUCTS_IN_ORDER_HISTORY_BOX);
Por lo tanto tienes que ponerlo en la clausula WHERE:
Código PHP:
$orders_query = tep_db_query("select distinct op.products_id from " . TABLE_ORDERS . " o, " . TABLE_ORDERS_PRODUCTS . " op, " . TABLE_PRODUCTS . " p where o.customers_id = '" . (int)$customer_id . "' and o.orders_id = op.orders_id and op.products_id = p.products_id and p.products_status = '1'
AND date_purchased > (CURDATE()- INTERVAL 1 YEAR) group by products_id order by o.date_purchased desc limit " . MAX_DISPLAY_PRODUCTS_IN_ORDER_HISTORY_BOX);
ó
Código PHP:
$date = date('Y-m-d',mktime(0, 0, 0, date("m"), date("d"), date("Y")-1));
$orders_query = tep_db_query("select distinct op.products_id from " . TABLE_ORDERS . " o, " . TABLE_ORDERS_PRODUCTS . " op, " . TABLE_PRODUCTS . " p where o.customers_id = '" . (int)$customer_id . "' and o.orders_id = op.orders_id and op.products_id = p.products_id and p.products_status = '1'
AND date_purchased > $date group by products_id order by o.date_purchased desc limit " . MAX_DISPLAY_PRODUCTS_IN_ORDER_HISTORY_BOX);
Si no es ese, será aquel que tenga el campo date_purchased.