Discuss with management the issues of late coming, timings etc-after studying the whole issue by practical observation and seeing the existing system already established in the office.
Once you are thorough with issues, then start drafting the timings for office which should be in consonance with shop act timings.
What all departments do you have- eg workshop, office, security guards, conservancy staff.
Timings will be different for these people.
Guards may be on shift.
Conservancy staff may have to come early for cleaning up and some may to stay till office closes.
Working hours within rules are given in Shops Act of the state.
Late coming can be decided like upto max 15 minute late then it will be treated as half day leave etc.
Whatever you do get the top management in picture and then only take actions if you are authorised.
Study,be thorough with rules/laws on the subject and give recommendations to your higher ups for corrective/amendment actions