Hi Pradhumn
Why do you think you will have to maintain the calendar year on year? This is going to be only a one time activity.
When the public holiday is created it is not made only for a particular year. Instead we specify only the date and the month in the PH. Once you are done creating all the public holidays just add these to the calendar and keep the calendar valid upto 9999 and you are done for all the years from the calendar perspective. The WSR also you can generate for next 20-25 years and you are all set then with no further maintenance.