Section 4(2) provides: "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: Provided that in the case of a piece rated employee, daily wages shall be computed on the average of the total wages received by him for a period of three months immediately preceding the termination of his employment, and, for this purpose, the wages paid for any overtime work shall not be taken into account: Provided further that in the case of an employee employed in a seasonal establishment, the employer shall pay the gratuity at the rate of seven days ' wages for each season." "Wages" has been defined in section 2(s) of the Act as follows: ""wages" means all emoluments which are earned by an employee while on duty or on leave in accordance with the terms and conditions of his employment and which are paid or are payable to him in cash and includes dearness allowance but does not include any bonus, commission, house rent allowance, overtime wages and any other allowance.