Manager: We (meaning you) need to do task A. How long will it take?
Me: Task A will take X days to do.
Manager: That seems awful long.
Me: How long do you think it should take?
Manager: It surely could not take any longer than Y days.
Me: Ok, it seems you have an answer to your question then.
Later:
Manager: It’s been Y days, why isn’t task A done yet?
That’s a good point.
Though sometimes people are just sandbagging. Like I know one guy is just watching Netflix instead of working. I’m downstream from his work, so it’s a little annoying that I have to wait a couple days to get started.
I wouldn’t rat him out because my labor solidarity beats out my annoyance, but the annoyance is real.