Leave Rules - Factory Act

As per the factory act 1948, Leave will be calculated for 1 Leave for every 20 days working. 240 working days will result approximate 15 days leave but the working should be previous year. Means You need to first Work for actual 240 days and then you can enjoy the same.

absolutely what you stated is correct. for every twenty days of working you need to give one day earned leave and 300 days would yield 15 days of leave. before that you need to check for eligibility for EL as per factories act. those eligible are only can avail EL accrued in the previous year.