Date & Time: 1:16pm MST
Frequency: Only had two opportunities to test it so far, but occurred both times
World name: Cactuar
Character name: Gwyn Unlucky
Monster name: Gaius Van Baelsar, Ultima Weapon
Class/Level: White Mage
Party or solo: Party
In-game time: 12:20pm
Area and coordinates: The Praetorium, Porta Decumana
Steps:
1. Complete duty The Praetorium or Porta Decumonta with ARR Relic at the light step (Thyrus Novus is the specific one I used)