Should Week Long Be Hyphenated?

You need a hyphen here, "long" doesn't stand on its own, it combines with "week" (or month, year, etc.) to form a single (or rather a compound) adverb. This is similar to the rule for compound adjectives: "two-seater", "friendly-looking", etc.

Is 2 week long hyphenated?

When "two-week" is used as an adjective, as it is in Sentence 1, it takes a hyphen and remains in the singular. There are many examples of this: It's a twenty-metre drop.

Do you hyphenate week to week?

Re: weeks or week

When using the number as part of an adjectival phrase, you need a hyphen.