These four events repeat every 'tropical' year (365 days, 5 hours, 49 minutes), so they become later by about six hours, or (if there has been an intervening leap day) earlier by about 18 hours, from one year to the next.
The three distinctive signs and symptoms of autism include problems with verbal and nonverbal communication, difficulties with social interaction, and repetitive behaviors or narrow, obsessive interests. There are three distinctive symptoms of autism.
0. Autism belongs to a collection of developmental disorders known as the autism spectrum disorders (ASDs). A spectrum disorder is a group of disorders with similar features. While one person may have mild symptoms, another might have more severe ones. Asperger syndrome. People with this syndrome display some of the milder symptoms of autistic disorder -- such as social challenges and unusual behaviors. They generally do not have any delays in language or impaired intellectual abilities.