A man-hour is a way to measure work: how much one person can do in one hour. If a job takes forty man-hours, that might be one person for forty hours, or four people for ten hours each — the number is about the work, not about one man’s day. Building sites, factories, and project plans use it. Though actually, many workplaces now say person-hour, because man was meant as “human,” but it sounds as if only men work. Same idea, kinder word. It is planning language, not chat. It is also not the same as “working hours” meaning nine-to-five.

人時（專案、工程用來算工作量）。日常說「工時」多半指上班時數，不完全一樣。