This document discusses the four seasons of the year, providing the start and end dates as well as length of each season. Spring begins around March 20th-22nd and lasts 90 days. Summer starts on June 21st and lasts 93 days at a north inclination of 23 degrees. Autumn begins September 24th and is 90 days long at zero tilt. Winter starts December 20th and lasts 90 days at a south inclination of 20 degrees.