Payment of Gratuity to some one who had worked part time initially

My query is :- we have an employee who was appointed on a part time basis i.e he used to come regularly for half a day, ever day, for more than one year or so. Later on his employment was made full time. Now the employee has resigned. so if we have to pay him gratuity are we to consider his part time employment for the purpose of calculating number of years or should we consider completion of 5 years from the date when his job was made full time with us.
Kindly advise. Request an immediate response.
Madhu Menon

1. For what purpose you hired Part time employee ?
2. Why you not hired him through contractor?
3. What is your current Provision to deduct PF & ESI for part time employees?

"he used to come regularly for half a day, ever day, for more than one year or so"
He will be entitled for gratuity as long as he complete 5 years continuous service.

Dear Sir,
As per the sentence made at the top the person has completed the Five years is eligible for the gratutity as per act
Regards,
sathyanarayanan T S
HR
NI Consulting Services Private limited
81, Peters Road
Chennai-600014.

Thank you all for your valuable replies.
Madhu Menon