It is normal for a 15 month old baby to sleep 15-16h/day. In general, the daily sleep time in childhood is related to the baby’s age, the younger the age, the relatively more sleep time. 15-20h/day before 6 months, 15-16h for 1-2 years old, 12-14h for 2-3 years old, 11-12h for 4-6 years old, and 9-10h for more than 7 years old, including the sum of daytime 1-2h naps and nighttime sleep time, which is the normal sleep This is the normal sleep time. Ensuring adequate sleep time is very important for children of all ages. In general, the light in the baby’s room should be soft, avoiding over-excitement before bedtime, and should have their own fixed-position beds to make the sleep environment relatively constant.