Data gets stored in a database table in exactly the same order that it was entered, ie new records go on the end.
What we do is to designate a Primary Key on one or more columns and this becomes the default sort order for the table. Now a primary key must be unique so you would have problems using your start date column for that: you would only be able to have 1 event per date if you did and I don't think that will work. You'll just have to create an index on the start date column and use an ORDER BY clause in your query.