Dolly Parton’s death date has “historically been important” to her goddaughter, Miley Cyrus, personally and professionally. Before Parton died on Tuesday at age 80 following a secret cancer battle, Cyrus opened up about the date when she released one of her biggest singles, “Used to Be Young,” in 2023. “I decided to release ‘Used to Be Young’ on Aug. 25 because this particular date historically has been important to me personally and in my career,” she explained in her ABC special “Endless Summer Vacation (Backyard Sessions)” in 2024. As fans may recall, Cyrus and Liam Hemsworth, who were 17 and 20 respectively, briefly broke up on Aug….