Does MySQL have time-based triggers?

I would like to execute a procedure periodically, how to do that in MySQL?

Are MySQL triggers synchronous?

MySQL triggers are executed for each row, and are synchronous (the query will not return until the trigger event finishes).

Are there triggers in MySQL?

A trigger can be set to activate either before or after the trigger event. For example, you can have a trigger activate before each row that is inserted into a table or after each row that is updated. MySQL triggers activate only for changes made to tables by SQL statements.

For which of the following MySQL triggers are not supported?

For which of the following are triggers not supported? Explanation: In MySQL, the triggers are run only after the table modifications like insert, update and delete are run. Triggers are not supported for views.

If you have MySQL 5.1 you can use events.

http://dev.mysql.com/doc/refman/5.1/en/events.html