There seems to be a fight going on within the New York City government, a statement equivalent to “water flows downhill.” In this instance, the fight is about parking (ditto on the water-flow comment). The fight plays out on signs posted around the city. According to the Fire Department, you cannot park at anytime” – one word:

Here you can park “anytime” – one word.

On the other hand, DOT, the Department of Transportation, goes for “any time” (two words): 

Now you can’t stop for “any time” – two words.

Which is correct? The Fire Department. As one word, anytime means “at any point in time – now, an hour from now, half past never, etc.” As two words, any time means “an amount of time,” as in “Do you have any time to waste looking for a parking space?”

The same formula is true for sometime and some time. You can come up and see me sometime (whenever you choose) to spend some time (an amount of time) with me. Well, actually you can’t. I’m shy.