As you are in Hubli, your establishment will be covered under Karnataka Shops and Commercial Establishment Act 1961.
I am enclosing a copy of the act.
Refer Chapter VI -15 Subsec 1 (1) Every adult employee is eligible for EL of one day per twenty working days.
You have to calculate on the last basic for the no of days he is eligible. Here you can refer Chapter VI 15 Subsec 7 para 2,
"Such carry forward leave should not be exceed 30 days"
You can apply this for your calculation and submit the fact to Labour Commissioner.
I HAVE ALSO ENCLOSED FEW MORE FILES FOR YOUR COMPLIANCE PURPOSE IN FUTURE TO AVOID SUCH EMBARRASSMENT IF ANY.
Excellent HR Services,
28th April 2011 From India, Selam