My DD#3 dropped to one day sleep around 8-9 months (much to my horror). We were (before school runs !!!!) late risers - wouldnt get up till 8am, so i just stretched her out till 1pm, and she would sleep till 330pm, back in bed again around 630-645pm......all kids are different, you may find your little one is not following the norm, but as you can see there are plenty of us that have experienced a 10mth old having 1 day sleep and im pretty sure they turned out okay...good luck !!!!