i can't remember exactly how old DD was when she dropped the third day sleep, but it was pretty early. I could never get her to go back to sleep once she woke up, she just liked her little catnaps! So don't stress if you can't get her back to sleep again. DD will now only have one day sleep, she started doing that a few weeks ago. Oh, and she now sleeps for up to 2 hours with just one sleep a day, even though when she was having more day sleeps she would be lucky to sleep for an hour!