These docs are for an old release.
Info on upgrading to v5
eventStartEditable
Allow events’ start times to be editable through dragging.
Boolean, default: true
You must enable the interaction plugin before using this setting. See code samples on the editable article »
This option can be overridden on a per-source basis with the startEditable Event Source Object option or on a per-event basis with the startEditable Event Object option.