Can you please explain clearly why you want to declare a holiday on September 2nd? If you think that the employees can enjoy the holidays consecutively (as September 1st will be a holiday for Ganesh Chaturthi) from September 1st to September 4th, you can declare it after discussing with your managers, PM, etc. Based on your work schedules, you can make the decision. This will make the employees very happy. You can inform them that to compensate for the holiday on September 2nd, that day will be a regular working day.
I would suggest discussing this with your company personnel. Visit
http://www.day-finder.com/ganesh-chaturthi-2011.html for more information.
Kind regards,
[Your Name]