'any time' vs. 'anytime'

My coworker asked me about this and I found myself stumped. In a sentence such as 'You can call me anytime", is ‘anytime’ the proper word or should it be ‘any time’? Or are both terms correct?

I was thinking of the difference between ‘everyday’ and ‘every day’ and wondering whether this is a similar circumstance, but now I’m not so sure.

“anytime” is defined in my Webster’s Third as “at any time whatever.” The example is “…can get a job anytime.” Does that clear it up for you?

“Every day” and “everyday” is actually easier. “Everyday” is an adjective, and means ordinary or commonly used. “Every day” is an adverb. Examples: “These are my everyday shoes.” “I wear these shoes every day.”

http://garbl.home.comcast.net/stylemanual/a.htm#anytime

http://www.wsu.edu/~brians/errors/anytime.html

Take your pick. You’re welcome anytime.

I’ve noticed how MS Word’s spell check is terrible about this. It doesn’t like those very first compound words you’ve been using since way back when. Someone at MS is in need of a grammar lesson…