OK, the 4 hours counted as below..
Normal working hours = 9am-6pm
On that day as I mentioned above,
I reached my office at 8am, waiting boss come to pick up to outstation.
when I reach location, its 9am, so I hv 1 hour OT in this case.
I suppose finish work at 6pm but I finish work at 8pm on that day, so i have another 2 hours of OT.
When I reached office, its already 9pm. From here, its another 1 hour of OT.
Total, I should have 4 hours OT claim, is it?
Thank you so much for your reply.