specifies the date in the header of the view
| date1 | Date | the date when an event is scheduled to begin | 
| date2 | Date | the date when an event is scheduled to be completed | 
Available only in PRO Edition
scheduler.templates.timeline_date = function(date1, date2){
    if (date1.getDay()==date2.getDay() && date2-date1<(24*60*60*1000))
            return scheduler.templates.day_date(date1);
        return scheduler.templates.week_date(date1, date2); 
};
The template requires the timeline plugin to be activated.
Note, if the timeline_date template isn't specified, the date in the header will be set according to the week_date template.