Tell Eric Robinson the date you were born and he'll immediately give you the day of the week you first drew breath. Same with dates in the future. He's a human calendar.

Yet, it's only weeks since the 19-year-old autistic savant mastered the buttoning of his own clothes, a feat that allowed him to trade elastic-waist trousers for his first button-up denims.His boyish tousle, poor coordination and craving for privacy notwithstanding, Eric will graduate June 2 from a special-education program that has taught him the joy of work in an alien world.

By the time he earns his diploma, his startled parents and teacher hope Eric will have found a humble life's work in numbers.

A recent issue of the Viewmont High School student newspaper dubbed Eric the school's "Rain Man." But while he shares many traits with the movie's title character, there are important differences.

Eric's calendar calculations and keen appetite for figures do not qualify him as a prodigious savant like the film's Raymond Babbitt, played by Dustin Hoffman.

But unlike Babbitt, who finally is repelled by life outside the solitude of an institution, Eric has shown he can use his mania for numbers and improving social skills to hold down a job. They loved him in employment trials at a video store and the school library.

Tests show Eric to be mildly mentally retarded as well as autistic and a savant, a rare mix that puts his promising quest for work in a post office or city library on a very uncrowded plane.

"He's just a huge success story for parents with autistic kids who normally feel isolated, frustrated and believe . . . it's a burden that will never let up," said Cindy Anderson, Eric's special-education teacher the past three years.

"I was worried because I had heard that they got worse as they got into adolescence and families had to decide what to do with them," said Candace Robinson, Eric's mother. "With Eric just the opposite happened. He just seemed to improve."

Autism, or absorption in self-centered, subjective mental activity, is a severe disorder present in four of every 10,000 births, an overwhelming majority of them males. Among its characteristics is a profound disability in forming normal human attachments, or in showing or receiving affection.

Robinson believes her son, who hoards bus schedules and loves to read the phone books he gets at Christmas, performs his calendar gymnastics by visual rather than mathematical means.

"I used to wonder if he was calculating dates, but I really believe it's a matter of having a photograph in his mind of our 100-year calendar. I asked him dates in the 1800s the other day and he couldn't do it," she said.

Still, he's a whiz at simple math and his memory for numbers is as convenient as it is vast. "He makes a great phone directory," says brother Dan.

The boy's social habits are steadily improving, Anderson said, citing Eric's response to the recent death of a school administrator's wife.

As expected, Eric affably recapitulated for the bereaved the obituary information he had gleaned from the newspaper. But then he added, "I'm so sorry about your wife."

Like the administrator, Anderson was stunned.

"The emotional connection is the last to be made by an autistic child," she said. "It's so difficult to make people understand the excitement you feel when they finally start making that connection."