^ this
Hours worked must be one of the worst metrics for performance, productivity, efficiency or commitment. I don't know why people in some countries or cultures are so obsessed with how long they work, or how few days they take off. Or actually, maybe I do know why, but it has nothing to do with 'amount of work done' or 'quality of work'.
I think that more often than not, the people consistently putting in the most hours are those who take the longest to finish stuff, and care the least about the quality of their output. Anyone can sit behind a desk 10 hours a day to impress the boss.
IMO no metric used to assess performance or productivity should include the number of hours present in the office. Instead of 'hours worked this week' or 'number of days worked this year', the metric should be 'total number of hours to finish the job', preferably divided by a factor based on the 'amount of rework or support required afterwards' and/or multiplied by a factor based on the flexibility of the person doing the work, both in terms of availability as well as skill set. Of course some of these things are hard to track on a spreadsheet, so they are rarely used.
Long story short: just try to do the best job you can in the most efficient way possible, without turning into a bean counter, just because that's the best way to impress your superior.