This. My industry is project based. We take the work when we can get it, and if it means piling it on in order to make sure we can keep a job that is offered we do it. Our techs are salaried, and they occasionally howl when too many hours in a week pile up. The funny thing is, we always offer to switch them to hourly pay scale based on their current salary and a 40 hour work week, where they don't get paid unless they are on the job site. Clams them up instantly. In all fairness, we have a great team that has each others backs and totally kick ass, and everybody steps up when it's crunch time. They just need to be reminded of how much they enjoy their Fridays off when it's slow :)
I know that all too well. Especially during the skiing and surfing seasons.
But on many a beautiful summer day, the following occurs: Boss walks into office. Boss: What are you doing? Me: Working. Boss: Do you need to get it done today? Me: No, but I'd like to. Boss: Too bad. Grab your helmet, we're going riding.