Greeting
According to Factory Act,1948 Every worker who has worked for a period of 240 days or more in a factory during a calendar year shall be allowed during the subsequent calendar year, leave with wages for a number of days calculated at the rate of-
1. If an adult, one day for every twenty days of work performed by him during the previous calendar year;
2.If a child, one day for every fifteen days of work performed by him during the previous calendar year
Explanation 1 . -For the purpose of this sub-section-
a) Any days of layoff, by agreement or contract or as permissible under the standing orders;
b) In the case of a female worker, maternity leave for any number of days not exceeding twelve weeks; and
The leave earned in the year prior to that in which the leave is enjoyed, shall be deemed to be days on which the worker has worked in a factory for the purpose of computation of the period of 240 days or more, but he shall not earn leave for these days.
For further clarification refer Factory Act,1948
Regarding policy you can frame as per your company policy because it differ from co’s to co’s
Regards
Surender