They might do it for short stints to "get ahead" if their scheduling allows it. If I know I'm going to get that extra time off in the future or I'm getting paid

They might do it for short stints to "get ahead" if their scheduling allows it. If I know I'm going to get that extra time off in the future or I'm getting paid for it (garaunteeing I was compensated for it) I might do it for a week or two to save up for a nice vacation or time off to do my own thing. As a manager or business owner... I'd never encourage it and possibly not allow it. The hours worked beyond 40 in a week often have drastic diminishing returns and increases in mistakes or poor thinking.