When creating a template on a more than one day event and try to apply it, the template does not remember how many days long is the event then the last day of the event is the same as the first day.
As the start time and end time are on the same day when the event is created with the template, either the event is created only one day if end time is greater the start time or it’s not created at all if end time is lesser than the start time (because event length would be negative).