The Day of the Sepulchral Night was a rare solar eclipse on Zelos II that occurred roughly every 120 years. When the planet's fourth moon was in line with the sun, the tides in the Great Zelosi Sea were at their lowest, which in turn gave access to Zelosian's Chine: an underwater mountain ridge.
The native Zelosians, superstitious of the event, stayed indoors for its duration.
- In 196 BBY; a shipwrecked merchant prince buried his treasure in Zelosian's Chine.
- In 4 ABY; the bounty hunters Solum'ke and Diergu-Rea Duhnes'rd found the treasure but were forced to abandon most of it when the cave began to refill with water.