I used to spend silly amounts of time hopping worlds and camping chinchompa spots, so this one hits home. In short: no, chinchompas in Old School RuneScape don't magically spawn more often at night — the game doesn't generally tie spawn rates to your local time of day. Spawns are governed by server ticks, area spawn tables, and
the hunter mechanics that control how and when creatures appear. What changes with night is usually the player population and the psychological feeling of availability.
Back in my hunting days I noticed a pattern: late at night there were fewer people in popular hunting areas, so it seemed like the chinchompas were everywhere. Really it was just
less competition; you had more free trap spots and fewer people world-hopping into the same node, so your catches felt faster. If you want more chinchompas, do what I did — pick low-population worlds, set up multiple traps if the method allows, and learn the typical respawn rhythm for that location, which comes down to practice rather than the in-game clock.
If you're trying to squeeze efficiency out of a session, the practical tips matter more than the time-of-day myth: bring proper gear, use a comfortable mousekey or tick-timed routine, and pick less crowded worlds. Night might help because of fewer players, but it's not a game mechanic — it's just better lighting for your own schedule. Happy hunting, hope you get the drop you want!