Very colloquial: más largo que un día sin pan
I remember Nicole posting something about not eating if she has no bread or something...jeje
Well, I don't think I am mistaken if I think that you are getting this one wrong....the meaning is really unusual.
Here we are talking about a person's height. 
Yes, rather strange.
Este hombre es más largo que un día sin pan.
A day without bread is unimaginable in Spain, we eat bread with everything...so something longer/taller in this case...is simply impossible to imagine.
6 Answers
We do have another one. That's longer than a month of Sunday's.
Here are a couple about the weather. It's hotter than a two dollar pistol shootin' uphill. Or. It's hotter than a burnin' stump.
I've heard, "he's taller than the day is long".
"as the day is long" is an intensifier that is used often to emphasize the adjective used to describe someone/something.
It is often associated with personal emotions/feelings/qualities:
as merry/happy as the day is long
He's as honest as the day is long
as industrious as the day is long
as lazy as the day is long
Shakespeare's much ado about nothing is generally credited with introducing this particular phrase into our lexicon; however, as is true of many assertions such as these, it is likely that a similar phrase probably existed this or was at had at least found some contemporary use prior to being published/acted in his play.
Interestingly enough. In German they say, "dumm wie die Nacht" (as stupid as the night) to describe utter and complete stupidity.
I've heard, "he's taller than the day is long".
Any suggestions as how to formulate a similar sentence in English?
I think what it is implying is that if you don't have any bread (or food in general) then the day seems to take forever. So that would mean the man is very tall.
