All I know is that 4 months would have been way too early for me to try to establish ANY schedule for my two girls (now 6 and 4) Not because I didn't want it - trust me, I did - it's just that trying to make a schedule just didn't work. Neither one of my kids took regular naps until about 8 months. Until then, they slept in swings, in my arms, in the stroller, wherever. Not the greatest for me, but I had tried everything but nothing worked. So, I guess my advice is this - some kids just can't get on a schedule until they're a little older. Oh, and I did do the Ferber method at night (can't remember how old they were, maybe 7 or 8 months?)? And it totally worked. If everything you're trying just doesn't work, you might have to wait it out a little. Good luck!!