The start date for an event isn’t actually stored in a meta_key on the event post. Those are stored in the esp_datetime database table, and can be retrieved using the models system. You can review an example of how the Event Espresso widget does its query which includes ordering by the datetime start date:
The support post ‘Meta key’ is closed to new replies.
Have a question about this support post? Create a new support post in our support forums and include a link to this existing support post so we can help you.
Support forum for Event Espresso 3 and Event Espresso 4.