Generally speaking, terms like few hours and few weeks refer to approximate blocks of time. They are often preceded by the indefinite article:
We can have your car fixed in a few hours.
Emily has been working on her paper for a few days.
That new movie is coming out in a few days. I can't wait!
but other words can be used in place of the article; for example:
My first few weeks on the job were nervewracking.
It has been very cold here for the past few days.
He always seems to perform well in the last few minutes of a big game.
It is possible to use "few" without such qualifiers, but the meaning is not the same:
Few days in my life were as miserable as that one.
In that case, "few days" is not a contiguous block of time, but refers to a small number of specific days. Similarly:
Few winters have been as cold as this one.
likely refers to non-consecutive winters (such as, say, the winters of 1993, 1979, and 1899), whereas:
It has been cold for a few winters now.
limits the scope of the discussion to the recent past.