You can refer Holiday notification of your respective state for confirmation.
E.g. In Gujarat state holiday notification no leave granted by Gujarat government for 1st May, 2019 labour day so need to give leave for 1st May, 2019 to employees.
Please refer leave notification of your state.
2nd May 2019 From India, Pune
Republic day, May day, Independence day and Gandhi jayanthi are National holidays.
If you do have a separate State Enactment on national and festival holidays applicable to industrial establishments and the particular day is specified therein as a holiday, you are obliged to grant holiday to the employees in your establishment or if they are required to work on such a holiday, they must be given the option of double wages for the day or an alternative holiday within three days before or after the day of the holiday.
It is not illegal to keep the establishment functioning on such national or festival holidays.
Any day on which the establishment works can be a date of joining for its employees if the situation warrants.
4th May 2019 From India, Salem