Hi Ranjith,
Calculate the no of days using the same logic. Use the following FM to add days to your start date.
CALL FUNCTION 'RP_CALC_DATE_IN_INTERVAL'
EXPORTING
date = '20131224'
days = 10
months = 0
* SIGNUM = '+'
years = 0
IMPORTING
CALC_DATE = lv_date2
.
Hope this will help you.
Regards,
Anoop