i have found in my experience as a home based carer/ nanny for the past 8 years (and a mum now too) from about 11 months to 14 months children move to having one sleep. i would recommend moving morning sleep forward by 15 mins each morning til u get to ideally 11.30/12 noon. if possible get out and about lots of playing helps see the morning thru then after lunch put DS to bed with perhaps a story/soft music so he knows it sleep time and try to re-settle if he wakes so he has a least an hour sleep for you. and for a short time until he stretches this sleep to an hour and a half /2 hours he may need a little nap around 3pm/4ish, but only let him sleep about 30mins and that way he's not too tired for dinner/bath time etc. it may take about 3 weeks to get into a pattern of changing from 2 to 1 sleeps. yes he will prob be a bit whingy once u start stretching him past his normal sleep time in the morning, i found going to a playgroup (and leaving a little early as mine finshed at 12) helped entertain the children, or park etc (be mindful thou of driving too far from home incase he falls alseep in car then lunch/sleep routine get a bit mixed up, i sometimes gave bigger morning tea then after sleep gave lunch). i think the 'perfect sleep routine' as suggested in some parenting sites say a mid-day sleep is from 11am-2pm (but i know very few people whose children do this - but, oh how nice it would be thou- so many more things i could do around the house if only DD had a 'perfect sleep routine') hope this is not too confusing as i'm getting a bit tired myself and going to bed... good luck, (you may have to change the time of the birthday party if his sleep patterns change b4 then, a friend of mine had their DS 1st birthday from 10-12noon, another friend started their DD party @ 3pm, more to think about, sorry)