Automatically set timestamps for "create" and "modified"?
From here: 

This limitation, which was only due to historical, code legacy reasons, has been lifted in recent versions of MySQL:

Changes in MySQL 5.6.5 (2012-04-10, Milestone 8)


  Previously, at most one TIMESTAMP column per table could be
  automatically initialized or updated to the current date and time.
  This restriction has been lifted. Any TIMESTAMP column definition can
  have any combination of DEFAULT CURRENT_TIMESTAMP and ON UPDATE
  CURRENT_TIMESTAMP clauses. In addition, these clauses now can be used
  with DATETIME column definitions. For more information, see Automatic
  Initialization and Updating for TIMESTAMP and DATETIME.


What can you do?

You can add a BEFORE UPDATE trigger and set the ts_modified to NOW() like this:

USE `test`;

DELIMITER $$

DROP TRIGGER IF EXISTS test.xyz_BEFORE_UPDATE$$
USE `test`$$
CREATE DEFINER = CURRENT_USER TRIGGER `test`.`xyz_BEFORE_UPDATE` BEFORE UPDATE ON `xyz` FOR EACH ROW
BEGIN

SET NEW.ts_modified=NOW();

END
$$
DELIMITER ;