e1 +05:00 CREATE EVENT `e1` ON SCHEDULE EVERY 1 DAY STARTS '2006-01-01 00:00:00' ON COMPLETION NOT PRESERVE ENABLE DO SELECT 1 latin1 latin1_swedish_ci latin1_swedish_ci
e1 +05:00 CREATE DEFINER=`root`@`localhost` EVENT `e1` ON SCHEDULE EVERY 1 DAY STARTS '2006-01-01 00:00:00' ON COMPLETION NOT PRESERVE ENABLE DO SELECT 1 latin1 latin1_swedish_ci latin1_swedish_ci
e2 -05:00 CREATE EVENT `e2` ON SCHEDULE EVERY 1 DAY STARTS '2006-01-01 00:00:00' ON COMPLETION NOT PRESERVE ENABLE DO SELECT 1 latin1 latin1_swedish_ci latin1_swedish_ci
e2 -05:00 CREATE DEFINER=`root`@`localhost` EVENT `e2` ON SCHEDULE EVERY 1 DAY STARTS '2006-01-01 00:00:00' ON COMPLETION NOT PRESERVE ENABLE DO SELECT 1 latin1 latin1_swedish_ci latin1_swedish_ci
e3 +00:00 CREATE EVENT `e3` ON SCHEDULE EVERY 1 DAY STARTS '2006-01-01 00:00:00' ON COMPLETION NOT PRESERVE ENABLE DO SELECT 1 latin1 latin1_swedish_ci latin1_swedish_ci
e3 +00:00 CREATE DEFINER=`root`@`localhost` EVENT `e3` ON SCHEDULE EVERY 1 DAY STARTS '2006-01-01 00:00:00' ON COMPLETION NOT PRESERVE ENABLE DO SELECT 1 latin1 latin1_swedish_ci latin1_swedish_ci
The following should fail, and nothing should be altered.
ALTER EVENT e1 ON SCHEDULE EVERY 1 HOUR STARTS '1999-01-01 00:00:00'