Honestly, I think a week is too long. I do think it's important to be consistent for a few days at a time when making changes, and some people will probably say a week is great, but I'm more impatient than that. I would only give each change 3 days. So stick with 3hrs for 3 days, then if his naps are still short AND you think it's b/c he's UT, not OT (I mostly make this choice by how happy she wakes up and/or how grumpy she is after the nap) and his nights are still pretty good, then up it to 315 for 3 days. Then up it to 330 for 3 days. But while you are doing this, i would still suggest getting in a 3rd nap if possible to avoid that 6 hr stretch of atime before bed. If you can manage even a 20 min catnap, it would help tremendously and you wouldn't have to increase the atime/push BT back very much for that as it is not nearly as restorative as a 30 min nap.
2nd, do you have to change him at night, or would he leak otherwise? Sometimes a size bigger diaper will help with leaks. Can you feed him in the dark (if you don't already) and then just put him right back down without changing him - it will help him not wake up quite so fully. What I do is just lather on the protective rash cream (night time is the only time I usually use it and I use it liberally) and leave her til morning. Her diaper is quite full in the morning, but it's never caused a problem. Once he starts STTN you won't want to wake him to change him anyway, kwim? Might as well start now... and if he's leaked before, it might have been b/c he was getting 20+ ounces at night, whereas now he's only getting 8 or so, so it might work now, whereas before it didn't.
HTH!! Good luck!!
