Days of Heaven (1978)

In 1916, Chicago laborer Bill accidentally kills his boss and flees to the Texas Panhandle with his girlfriend Abby, posing as siblings to avoid suspicion. They find work on a wealthy farmer's estate, where Bill learns the farmer has a year to live. When the farmer falls for Abby, Bill urges her to marry him, hoping to inherit his fortune. But as the farmer's health lingers and jealousy grows, the days don't seem to come as quickly as they want.