Haha, I'm a big fan of the 'I need this by Thursday' (or whatever day) statement. I appreciate it probably means by the end of the working day i.e. around 5pm, but I have occasionally left it to 11pm and then argued that it was still on time! I wouldn't recommend this approach as it does tend to piss people off, but I think you're fine to leave it to the end of the 'working day'! Best, KB