In all honesty, many knowledge worker jobs in the US are already un-clocked. Essentially, the company has an expectation that a job gets done and the employee has an expectation that they'll generally speaking be present at the office roughly during core hours. The unspoken agreement is that this ends up being roughly 40 hours per week, with concessions made on the employee's part when things get tough and on the employer's part to offset the aforementioned extra time.

Ultimately, this serves the employer's purposes more than the employees', but it's better than the bad old days of clock-in, clock-out. Imho, most managers [at least in tech companies, but not just the big name tech companies] operate this "just get your job done" way.

This is especially common in the Bay Area where a fair number of folks have 1.5-2hr each way commutes.