If a friend invited you over "after work" and neither of you had a 9-5 job (I mainly work school hours and he finishes around 8 or 9pm), should it be obvious what time they expect you? Especially if they don't want you to come straight from work as it's too early and they actually have the day off anyway. And would you be annoyed if you tried to clarify when they meant and they just repeated "after work" and then went silent?