Time spans are periods of time that can range from very short to very long. The three crossword solutions for the term TIME SPANS are ERAS, EONS, and YEARS. ERAS are long periods of time that are usually associated with a particular period in history or prehistory. EONS are even longer periods of time, often used to describe the age of the Earth or the universe. YEARS are the shortest of the three, referring to the amount of time it takes for the Earth to orbit the Sun.