Sometimes we need studies to point out the obvious, just so there's some science behind it. Like this: A new study at Cornell found that working outside your normal schedule can make you dislike your job.
One example would be having to check in at night and respond to emails. But it also applies even if you're not adding extra hours to your day. Even if your boss makes up for it by letting you come in late the next morning, it still has a negative effect.
They think it's because it interferes with time you've already "mentally encoded" as time to yourself. And also because it messes with our "collective time off," meaning time when your friends and family are also free.