I have created a event to run EVERY 1 DAY at 3:15 (am). I know that timezones affects events and actually I create a query to check the START time in mysql.event (GMT timezone) and information_schema.event (Local system timezone/EST for this example).
As you can see in the image below, my event is supposed to run every day at 7:15 GMT or 3:15 EST but following the two last columns %lastExecuted% you can see tha actually it ran 4 hours and 15 minutes later than expected.
This is the creation code:
CREATE DEFINER="vpladmin"@"%" EVENT "call_biz_review_lookups" ON SCHEDULE EVERY 1 DAY STARTS '2019-05-03 03:15:00' ON COMPLETION PRESERVE ENABLE DO BEGIN INSERT INTO..... END