A general rule for hyphenation is that phrases used as an adverb do not use hyphens while phrases used an adjective do. Such is the case with up to date vs. up-to-date.
Up to date is an adverb phrase meaning that something was brought current. For example, Our supervisor required us to bring our accounts reports up to date. It does not take hyphens.
Up-to-date is an adjective phrase that means something includes the most recent information. To wit, Molly’s up-to-date history textbook includes the results of the last presidential election. It needs hyphens.
Knowing whether or not you need hyphens is simply a matter of determining which word the phrase modifies. In the first example given here, up to date modifies brings, which is a verb, so you have an adverb phrase and no hyphens. For the second example, up-to-date modifies textbook, which is a noun, so you have an adjective phrase and hyphens.
Up to Date vs. Up-to-Date – When to Hyphenate?
