Overtime & Sick Leave application on the same day / minimum hour of rest for shift worker

1)      Can a worker claim overtime while he also apply sick leave on the same day? My company is allow shift worker to start work earlier than their actual schedule. For example a worker supposed to start work at 7.00 am but he clock in at 6.00am and consider he work overtime for 1 hour. But what if this employee come in 1 hour early and later he fall sick and apply sick leave on the same day? Should we paid him that 1 hour OT but in fact that worker didn’t perform overtime as he didn’t complete his shift for that day? 
Overtime allowance is payable if the employee is required by the employer to work above the limit of working hours specified above. All work in excess of the normal hours of work (excluding break time) is considered as overtime work.

For the scenario you have provided, your worker has not perform the normal hours but only work for an hour before he applying for Sick Leave on the same date. You shall talk to the employee that with Sick Leave given on that specific date, the hour from 6am to 7am shall not be treated as Overtime as he has not worked for the normal hours of work for that day and he has been certified to be unfit to work for the whole day.

2)      What is the minimum hour rest for shift worker between 2 shift? I can’t find any regulation on this matter in the employment act. I’m wondering can I ask worker to come back to work 8 hours later after finished his previous shift. If not, what is the minimum rest hour is allow in between 2 shift for shift rotating worker?
Under Section 40 of the Employment Act, shift workers can be required to work more than 6 consecutive hours without a break, or more than 8 hours (but not more than 12 hours) a day, or more than 44 hours a week (but not more than an average of 44 hours per week over a period of 3 weeks. You can claim overtime, if you work more than an average of 44 hours per week over a period of 3 weeks.
You may plan the rest hour in compliance to the above and assure 1 Rest Day of any continuous period of 30 hours of a week (need not be a Sunday).