I have some problem with Leave calculation..!!

I want to know that on what basis anual leave is given. The Factories Act says
" 79. ANNUAL LEAVE WITH WAGES. – (1) 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 – (i) if an adult, one day for every twenty days of work performed by him during the previous calendar year; "

but our company gives 30 Days leave after completion of 240 Days to Staff members and 20 Days to Workers.

I want to know is that :-

1] Is there any specific nos of leave fixed by the Act or depends on company policy.
2] Also need the break up (CL+PC+SL etc)
3] How many leave can be carried forward for the next year
4] And on what basis the leave encahsment can be done ?

Please help on this matter

Best regards

Sunil
"It’s better to be an authentic loser than a false success, and to die alive than to live dead."