Not to be confused with är!
Definitely not. :) Since this comes up often, I'll take the opportunity to point out for learners that the letters å and ä are completely different letters in Swedish, just as different as e.g. g and p.
Why is "a complete year" incorrect?
It's not really an idiomatic English phrase.
So a year is neuter and a month is common gender?
How do you say: a total year in Swedish?
fullständigt, probably, but it depends on what you mean by it.
Why is hela Stockholm right if its not plural?
hela is also the definite form.
why do I have to put helt and not hel?
år is an ett-word. So it's the same reason you use ett instead of en.
Is it my ears, or does the audio sound like ett hel dår?