One place I worked the boss used to set ridiculous unachievable deadlines and I was constantly having to say "The machine/computer/anything non human takes 'this' long therefore no... it cannot be finished 3 hours earlier!" here I was seen as a trouble-making young woman for arguing with the boss. When I moved jobs the new boss would ask me how long a task would take, my experience with my previous boss led me to come up with the x2 idea without anyone ever telling me about it. In that job I was praised because I always finished the work far earlier than was expected. :)