> you simply come up with a measure of how long it should
> reasonably take, double that and go to the next unit of time.
> Example: Replacing a hose should take three minutes. 3 x 2 = 6 hours.

My wife has developed a similar formula for when she asks me how long
something (Vanagon or otherwise) will take:
"It'll take 5 minutes" means "one hour"
"and hour" means "the rest of the day"
"a couple days" means "two weeks"
and
"I'll have that blown engine swapped out in a month" means "OMG that
Vanagon is never going to run again, is it!"

It's odd, because when I'm quoting time to do a job for a customer, I
can nail the time almost spot-on every time; but when it's one of my
own projects, my optimism completely overwhelms that skill...

The engine swap only took 5 months.

--
John Bange
'90 Vanagon - "Lastwagen"
'90 Vanagon GL - "Wiesel"