As far as we pay the salary on a monthly basis, including Sundays and other holidays, trhe earned leave will have to be calculated on a monthly basis only. It may vary from company to company. In the normal course, one day a month is given as earnwed leave and thus 12 days per annum. Casual leave is also for 12 days in an Year but cannot be carried over to tghe next Year whereas the eraned leave can be accumulated upto 3 Years. Sick leave is also calculated as one day per month and can be accumulated for 3 Years. In US standards, the suick leave is for 5 days and other leave ( whether eanrned or casual) is for 10 days.