have had its/(one's) day
To be past the highest point of success or potential in life. My father has had his day. Now, it's time he let his children take over the family business. It often seems that letter writing has had its day.
had its day, has
Is no longer useful or popular or successful, as in Some people think the railroad has had its day. This expression is the antonym of have its (or one's) day, meaning "to experience success or prosperity," as in Every dog has its day, a proverb dating from the 16th century. Both terms use day in the sense of "a propitious or opportune time."