Surely it is entirely role and sector dependent?
I work on customer services in a supermarket, my start time is the time at which I need to be at the desk and ready to serve customers, not the time at which I'm strolling in the staff entrance, still needing to hang up my coat, clock in and head out to the shop floor. Additionally, if I am working second or third shift my start time is more than likely going to be someone else's finishing time so if I'm strolling to the desk at 5.10pm then the person who was supposed to finish at 5pm has had to stay 10 minutes late.
I use public transport so I tend to arrive at the store about 20 minutes before my start time, which is perfect for me as it gives me time to get in the building, hang up my coat and put my bag in my locker, change into my uniform if necessary (eg if it is particularly wet/hot then I don't want to have to work in damp/sweaty uniform so bring it to change into), nip to the loo and then have a chit chat in the canteen with all my colleagues who are on break before I go down, clock in and start work.
The way our system works that I am paid from the second I clock in until the second I clock out, but to get to the clock in machine I have to walk in the staff door, go upstairs, through the staff area, go back downstairs and it is located just inside the door to the shop floor. It would be very obvious if someone came in, clocked in and then went back into the staff area to get ready and they would be pulled into the office as you are not supposed to clock in until you are ready to work.
Most of us are pretty flexible though - we all aim to clock in a couple of minutes early so that we have time to walk to our station, have a quick handover if necessary (not needed on checkouts but needed at the CSD) and the person you are releasing can be out of the door at 5.02.