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.
There are three different types of Autism Spectrum Disorders: 1  Autistic Disorder (also called classic autism) This is what most people think of when hearing the word autism.. 2  Asperger Syndrome. People with Asperger syndrome usually have some milder symptoms of autistic disorder.