Anytime vs. Any Time

As English is an ever-evolving language, words are often caught mid-change. The adverb anytime is currently evolving; in common usage, it may be written as one word, but in formal communication it should be left as two words.

Quotation marks may be used any time a character is speaking.

This sentence is obviously formal, so a compound word would be inappropriate here.

My new bicycle allows me to go anywhere, anytime.

In this sentence, anytime is acceptable as a compound word because the sentence in informal; it’s not the kind of thing one would write in an essay or proposal.