I have a story about the boss: years ago the boss walks over to me and describes a straightforward change with priority that it should start right away. I said it was a two or three day job and that considering testing and other internal process could be confidently delivered in two weeks. "That's too long, never mind". I then overhear him asking a coworker about the same project. He says: "Easy, that is a two or three day project", "great!".
What happens next? The project was delivered after two weeks due to back and forth testing and integration, debugging, etc.
Had a boss that did this, but always picked the overconfident, unreliable, under-bidder. He was incapable of bidding anything in increments of days/weeks. Everything was "an hour" to "an afternoon".
So I'd say "2 weeks to complete end to end".
The other guy would say "I'll crank it out this afternoon".
Other guy would deliver code that wouldn't run, and then require 3 weeks from me, QA, and him to actually massage into something that works the right way.
So instead of 2 person-weeks, it would take like ~5-6 person-weeks all in. Great stuff.
My conclusion in former years was that I had won, as I’d been right. But my conclusion now is that the other employee won, as they get to deliver the software, increase their “power” as they now know about one more piece of software or feature (on account of having written it). The overrun will be forgotten, but “this person delivered the feature” will be remembered.
What happens next? The project was delivered after two weeks due to back and forth testing and integration, debugging, etc.