I’ve worked crazy hours for weeks at a time learning a new to me technology or trying to figure out something. I purposefully, don’t tell anyone that I’m working late or on weekends and I don’t send or respond to emails outside of office hours. When I was Dev lead, I recommended no one send or respond to emails outside of normal office hours. If they were really having an issue or wanted to work late to figure out something and they had a quick question, I would sometimes answer over Skype but I would never communicate outside of the team or with management outside of office hours unless something was blowing up. Even then, my manager would have to call me or Skype me. I told them that I don’t have work email on my personal phone.