Assuming you mean editing, really you shouldn't be submitting a novel (or anything, really) until you're happy that it's the best you can reasonably get it.
Honestly you should be dumping as much time into the story you are planning on submitting to the publisher as possible. You want that piece of work to be the best it can possibly be, to embody everything that you stand for as an artist. There is no use in rushing if at the finish line they shake their head and tell you its a piece of junk.
there's no general time frame... some writers can polish their mss in weeks, some take years and never get it there...
