Gujarat used to follow Bombay Shops and Commercial Establishments Act.
Now the following is also available amongst publications.
All applicable enactments must be available at the website of Dept. of Labor of Gujarat or you can buy from market. It shall be appropriate to retain the services of a Labor Consultant/Service lawyer/law firm well versed with state laws.
Your establishment is extracting 8.30hrs of work/day and 49.30hrs/week and should pay OT.
>>> THE GUJARAT SHOPS AND ESTABLISHMENTS ACT, 1948
[Act, No. LXXIX of 1948]1
[11th January, 1949]
Sec2: (19) "Period of work" means the time during which an employee is at the disposal of the employer;
Section 13 - Opening and closing hours of commercial establishments
Section 14 - Daily and weekly hours of work in shops and commercial establishments
(2) Any employee may be required or allowed to work in a shop or commercial establishment for any period in excess of the limit fixed under sub-section (1), if such period does not exceed three hours in any week.
Section 15 - Interval for rest
[(1)] The period of work of an employee in a shop or commercial establishment each day shall be so fixed that no period of continuous work shall exceed five hours and that on employee shall be required or allowed to work for more than five hours before he has had3[an interval for rest of at least--
(i) half an hour, if he is employed in a commercial establishment engaged in any manufacturing process, and
(ii) one hour in any other case, subject, however, to the provisions of sub-section (2)].
Section 17 - Spread-over in commercial establishments
>>> Factories Act -1948
OT: 2 hrs/day…. not exceeding 12 hrs/week….50 hours in a quarter.
The ILO has advocated to bring down work hours to 40/week. It is however not implemented in India!
There are many threads on work hours and OT that you may find interesting e.g;
https://www.lawyersclubindia.com/forum/Working-hours-100706.asp#.U0jhTEeBmXU