Please note that, as per The Payment of Gratuity act. 1972 under section 2,-A, its mentioned the continuous services, means, employee shoud have work continuesly minimum for 5 yrs without interrupted of services for become eligible for Gratuity.
So, as per section 2, One year shall be consider with minimum worked for 240 days by employee & for six months service shall be consider for minimum worked for 120 days.
its means, someone worked for 4.6yrs, then his 6 months services shall be consider as one year subjected minimum 120 days worked during this 6 months, then he / she become eligible for 5yrs of gratuity amount.
I hope above provided details are satisfy your query.
(ACHRM, MBA-HR, DLL(Hons) In Labour Laws.