If an employee joins the company on 1st December then how much leave he will get after the probation period?

Please guide how to calculate leave on a pro-rata basis? I mean what is the formula?
if an employee joins the company on 1st December then how much leave he will get after the probation period. ( after 6 months )
In the probation period employee liable for medical on any kind of leave?

@HR_MPW
leave rules are fully controlled by management and the concerned HR, as your query is from United States, so you can ask your HR to know better for festive and gazatted holidays leave
in India the employees 1 EL for every 20 days attendance which is claimable after the calendar year close