They just are. Even the ones who say they aren’t. So make it easy on yourself and your team. Whatever time they give you, at the very minimum, increase it by 20% in your head and on your projections at the very minimum. If you can, take whatever they gave you and double it in your projections. If you do this, you will almost always make your deadlines. Never go below a 20% increase in your projects, ever. Don’t tell them that you’re doing this, just do it and keep it to yourself, then smile when they make the deadline you thought they would make in the first place or beat your expectations.