Hi UmeshV Pandey,
It is a very big offense to employees, Since every one will have their own commitments and employees majorly has to plan their commitments as per the pay of company. So, You will defiantly face a big challenge if you try to convince employees, Instead plan a fixed Payroll day and communicate the same to all employees in advance, In order to ensure the salary credits as per committed date.
For this, U need to Have a discussion with Management, with a prior observation of maximum delay that is happening on every month and propose a fixed date to management considering the maximum delay happening on every month, ensuring they will be confident enough to accept the date you refer, And put the matter in such a way conveying the importance of PAY ON TIME, And the impacts of the regular delay of payments. Since, The date your referred has already mentions the maximum delay date(take the maximum delay happened from the last three months), Management will accept for the proposed date for sure.
Here you need to remember that, PAY ON TIME does not refer the salary payment on the first working day of the month or last working day of the month, but Its more of paying employees as per the communicated dates.
So, As this approach provides a maximum buffer time for the management to arrange the salary funds and Ensures Employees pay as per committed date , You can actually come out from this issue, Instead trying to convince the employees.