No, they are not weeks, and the minute "we all know it" you are fucked. Engineers are not concerned with time. They are concerned with feature completeness and

No, they are not weeks, and the minute "we all know it" you are fucked. Engineers are not concerned with time. They are concerned with feature completeness and quality. They do not care how long a task takes, only that it is done Right. When the PM asks how hard it is, that's their only consideration. The PM only cares about time to make accurate predictions for the rest of the business. A given task takes as long as it takes to be done Right. If the business wants it on a different timeline, the business has to redefine the task, or redefine Right (ie skipping tests or doco). Research bears it out: human brains suck at estimating time, and are much better as soon as you talk in terms of effort. BUT if you want to insist on brute forcing through our cognitive biases, I have good news: you can do almost as well by tracking the relationship between "developer time" and "real time". You're still dealing in abstracted units, of course, but you can still pretend you aren't, which is the important thing.