While nature offers four seasons, Wall Street offers only one—four times a year. It’s called “earnings season,” and it can move the markets. So what is earnings season and why is it important? Earnings season is the month of the year that follows each calendar quarter-end month (January, April, July and October) in which many public companies release quarterly earnings reports. Other public companies report earnings at other times during the year, but many are on the calendar year that ends December 31.