James Hurst, the author of "The Scarlet Ibis" uses the changing seasons and Doodle's age to show the passing of time.  Throughout the story, Brother places special attention on the seasons as he retells the tragedy of Doodle's life in a flashback.  The story opens on the cusp of autumn, or "the clove of seasons" as Hurst describes it.  We learn about Doodle's accomplishments at the age of two when he can lift his head and begins to crawl.  We are later made aware of Doodle's progress in the spring when he is five, and Brother tries to teach him to walk.  On Doodle's sixth birthday, October 8th, he walks for his parents for the first time.  The winter season is mentioned in the story when Brother admits that they didn't make much progress on Doodle's ability to swim and climb a rope.  Again, time passes through the summer when Daddy loses the cotton crop to a storm.  The story comes full circle towards the end when we again reach the "clove of the seasons" Brother mentions at the beginning of the story.  

By using seasons and defining times in Doodle's life, we not only realize how short Doodle's life is, but how he is impacted by the passage of time.  His entire life is a struggle, and that struggle is played out with every season and every demand Brother places on him.