Q: Take the name of a well-known actress. Her first name starts with the three-letter abbreviation for a month. Replace this with the three-letter abbreviation of a different month, and you'll get the name of a famous poet. Who are these two people?
At least there are only 12 months to deal with, not 13.
Edit: The actress played President Alma Coin from District 13 in "The Hunger Games: Mockingjay" (Parts 1 and 2).