A period of time which approximates to within 4-6 weeks in Gregorian Time. It's context is specific to generic timeframes provided by inexperienced estimators.
eg It will be delivered in a Hafer.
eg It will take a Hafer to complete.
eg That operator told me on the phone it would take Hafers of time.
To disapprove of anything and everything even remotely related to fun, enjoyment, and laughter.
Friend: "Wanna come puddle jumping with me?!"
The Hafer: "Puddle jumping? What are you, three?"
Other Friend: "Dude, you're such a Hafer. Stop Hafering."