Changes in sleeping patterns

Casey

My twins are three days shy of 11 months old and in the past week their sleep has been really weird. They used to sleep from 6:30/7pm to 7am on the dot, now they're sleeping until 8am or later and still taking two naps a day (1-1.5 hrs per nap). Just curious if them sleeping longer might be a sigh they're getting ready for just one nap a day? Looking for thoughts, opinions, experience. Thank you!