Any tips for lengthening naps?

[oysterpots]

DS goes through strange phases with his sleep - he had been only having 3 45min naps a day (he's 11mo) but we knocked the late afternoon one on the head a couple of months ago. After that he began sleeping longer after lunch - sometimes up to 2 hours or so.

But, thinking about it now, since he started doing that he began waking at 5am. The past week or so he's reverted to a 45 minute nap after lunch but is sleeping until 6.30am.

He always has a morning nap for an hour or so, sometimes longer.

Is he getting enough naptime sleep? Is there any way to extend these naps? Or is he just changing his ways and maybe will drop the morning nap in favour of a biggie after lunch? I know the latter is what the nursery will favour, and he's starting in August so perhaps it's worth working towards that. What tips??

[didsnbump]

From what ive read all they should need is 3 hours daytime sleep from 6 months onwards, not sure when after 12months it reduces.

My ds is 5 1/2 months and seems to sleep well at night with the following nap times, 9.30am-10am, 12am-2pm, and then half hour some where between 4pm/4.30pm!

I find if he sleeps longer then half hour in the morning he wont sleep for 2 at lunch time. But if he doesnt have an afternoon nap he gets overtired which seems to affect the full nights sleep!