Where does Cinderella take place?

Charles Perrault's version is much more common since Disney adapted it in 1950. My guess would be sometime in the 17th century.

There's a web page (link below) featuring many versions of Cinderella, including that by Charles Perrault and that by The Grimm Brothers.

About the time - there are versions of this as well, but they all lead to one point: we don't know. It's a time outside ours, in a universe filled with magic, in which beautiful girls had fairies as their godmothers.

Some hints in the story would point to the Middle Ages, perhaps. But finding an approximate time setting for a fairy tale isn't the most worthy of endeavours. This is a quote from one of the versions, that I find most eloquent:

Once upon a time, though it was not in my time or in your time, or in anybody else's time