Timeline (Gantt) chart showing both hour and date

Hi all
I am trying to make a timeline chart showing both hour and date. I have attached an example file wherein I have plotted timelines in hours. What I want to do is to show the dates as well in primary or secondary axis so that viewer can get the date of finishing various jobs. From hours only one has to calculate. I want date should start at zero hour and every 24 hours next date should be seen. Plot can be made directly with date only but if one job finishes sometime in the day and another job starts same hour and not next day then it is problem to plot realistically. Hope I could make it clear. Please guide.