Yearly increment month change - is the company liable to pay the arrears to employees?

In my company prior to my joining, the yearly increment was being carried out in the month of Oct. But this year, the management decided to do the increment in Mar 2018 instead of Oct 2017. So, is the company liable to pay the arrears to employees from Oct? Please note increment month is not mentioned in our company employee handbook. We are registered under the Goa Shop & Establishment act.

For increment there is no any Statutory Act/Law but if it is delayed then employee may start looking for better opportunity outside.

Dear Sandra,
Salary/wages and its structural composition etc., are, initially,matters forming part of the contract of employment and its periodical revision is subsequently a matter of collective bargaining or in the absence of collective bargaining, a matter of discretion of the employer subject to legal restrictions, if any applicable to the establishment. Therefore, by implication, "increment" refers to the amount of periodical hike with reference to the initial salary or wages as agreed between the employer and employees. In the absence of any such agreement, it can not be claimed by the employees as a matter of right as long as the existing wages do not fall below the statutory minimum wages. In my experience, those employers strictly adopting the statutory minimum wage rates do not grant any periodical increment as the dearness allowance is revised periodically every six months or every year.

Thanks a lot for the valuable advice.