How To Calculate Interest On Delayed Gratuity..?

Hi, Can someone guide..
After resignation within 30 days gratuity is become payable, If not paid within 30 days than 10% ROI (simple is payable).
Gratuity Formula = Last month basic x 15 x No.of Years of Service Completed / 26 (no of days in month)
How to calculate the Interest amount? Which is the option will use, Option 01 or Option 2 ?
Interest Formula - option 01
Total delayed gratuity x 10% (ROI with simple interest) x No of days delayed / 26 (no of days in month)
Interest Formula - option 02
Total delayed gratuity x 10% (ROI with simple interest) x No of days delayed / 365 (no of days in a year)

Hi,
claim interest will be deciding through Controlling Authority. and generally we say 10% interest P/A on delayed amount. option 2nd is correct.