This is more of a thought experiment more than anything else. But let's say for argument's sake that a client had a contract in place with a worker for 100/hr. And also for argument's sake, the worker is a bit cheeky and decides to charge the client for work down to the level of seconds. The worker also has verifiable logs of every second work.
If the worker charged for 1hr 12 min 39 seconds, and the client refused to pay for more than the hour, what would happen? Would the judge simply throw it out? Is there some merit to the hypothetical worker's case?
EDIT: Answer for the US Jurisdiction for which you are most familiar