When does Olive Kitteridge return?

The HBO miniseries is based on Elizabeth Strout's 2008 novel Olive Kitteridge. Frances McDormand plays the title character and Richard Jenkins as Olive's loving husband. The show is divided into four parts, each depicting a certain point of time in the novel. It debuted in the United States on November 2, 2014, on the American premium TV network HBO.
Olive Kitteridge is a misanthropic and strict, but well-meaning, retired schoolteacher who lives in the fictional seaside town of Crosby, Maine. For 25 years, Olive has experienced problems of depression, bereavement, jealousy and friction with family members and friends.