Automatically update 'To:' field in ikhal if start date is after end date

When I edit an event in ikhal (say, I want to move it from today to tomorrow) I can modify both the start date ('From:') and the end date ('To:'). But I have to modify both of them. If I only change the start date and hit Save, I get the message: Can't save: end date is before start date!.

It is obvious that the end date must be after the start date. Would it be possible for ikhal to detect that a user modified the start date and, if the end date is now before the start date, update the end date automatically (that is: set the newly inputed start date as end date)?

I don't know if this feature would be useful for other users too, but it seems that way to me. Also, I don't know if it's possible in urwid to react on events (such as 'user selected end date field' or 'user has left start date field'), so I don't know how much problem would it be to implement this.

Start by locating ikhal's event editor and the From:/To: fields, then inspect how the urwid form handles date changes and validation. The change is done when editing a start date that passes the end date updates the end date automatically and the event saves without the existing error.