Where I work they ask me how much time a certain task will take, but they still go with whatever time the PM/Manager thinks it will actually take, then they com

Where I work they ask me how much time a certain task will take, but they still go with whatever time the PM/Manager thinks it will actually take, then they complain when things get late. I once had a huge discussion with the Architect because I said something would take an year to finish and the Architect was claiming it would take 2 months. He would not understand that the remaining 10% of the task would take 90% of the time (yes, it was partially complete and I had been following its development from the start, although never involved in it directly). In the end they went with his estimation but it took 2 years to finish the thing. Still, I think estimation is important, once you actually listen to the estimations and understand it really depends on who is doing it.