Dear Mr. Laxam Manoji,
As per the Gratuity Act, gratuity is calculated only when worked for 5 years or more with continuous/uninterrupted service, with each year completed 240 days of service. Therefore, if one has worked for 4 years and 240 days (in the preceding year, i.e., the fifth year), they are said to be eligible for gratuity.
Refer to Gratuity Act, u/s 2A: Continuous service.
(1) An employee shall be said to be in continuous service for a period if he has, for that period, been in uninterrupted service, including service which may be interrupted on account of sickness, accident, leave, absence from duty without leave (not being absence in respect of which an order treating the absence as a break in service has been passed in accordance with the standing order, rules, or regulations governing the employees of the establishment), layoff, strike, or a lock-out or cessation of work not due to any fault of the employee, whether such uninterrupted or interrupted service was rendered before or after the commencement of this Act.
(a) for the said period of one year, if the employee during the period of twelve calendar months preceding the date with reference to which calculation is to be made, has actually worked under the employer for not less than -
(i) ninety-five days, in the case of an employee employed below the ground in a mine or in an establishment that works for less than six days in a week; and
(ii) one hundred and twenty days, in any other case.
For every completed year of service or part thereof in excess of six months, the employer shall pay gratuity to an employee at the rate of fifteen days' wages based on the rate of wages last drawn by the employee concerned.