It's voluntary. We're all salary and a portion of our bonus is based on hours worked. When I did the occasional 100 hour week (also voluntary; I work on fun stuff) and forgot to log my hours, I would get credit for it, but there wasn't a direct metric for compensation.
We started adding in other employees in multiple departments cause they liked it better than manually tracking.
We started adding in other employees in multiple departments cause they liked it better than manually tracking.