you have already received some excellent advice in this thread from some excellent
advice givers (pleonasm not necessarily not unintended).

i guess this question is to everybody, and not just to the original poster. as someone
that hides from real accountability in academia, i have limited experience with project
managers who define deadlines, but i have a lot of experience of people that ask a lot
of you with short notice. a personal peeve of mine is the continual delayer - the kind
of person that says it'll be done by x, then by x + t1, then x + t2, then eventually it
is delivered at x + tn (t1 < t2 < ... < tn), so i vow never to be one. in a situation where
the delivery date will be difficult, i will say so quite directly. then at least something
can be done to help (getting more people in, discuss adjusted deliverables like swgh
said). so my question is this: in the real world, how do PM's react to early projections
of late delivery? of course it depends on so many conditions, but in general, do they
prefer "I will need need an extra month or an extra guy" at the start of a project or
a "I will be a week late" at the end?