Dear Roshni,
1. Only Earned Leaves / Paid holidays are mandatory under Labor laws.
2. Casual Leaves are as per convention are between 10 to 12 days per year. These can be preferably 12, as can be spread equally over each calender month.
3. Shops & Establishments Act declare every year specific 10 days as holidays. These include Republic day, Gandhi Jayanthi, May day, some festivals falling on working days etc. These Ten days are mandatory holidays.
Hope you, now, stand clarified comprehensively.
V V PRASAD CS