Perfect Day was a short story published in the Doctor Who Yearbook 1994. It was written by Mark Gatiss.
After dropping off the Gravis on Kolkokron, the Doctor takes Tegan to the day the Earth is destroyed, where they meet two people, an old woman and a crippled boy, calmly waiting for the end to come.
- This story equates the end of the world seen in The Ark with that mentioned in Frontios.
- Tegan recalls Nyssa telling her about the destruction of Traken. (TV: Logopolis)