"When's the next eclipse visible from here ? " sounds like a lookup. It's actually two hard problems stacked on top of each other: predicting when an eclipse happens, and predicting whether it's visible from one specific point on Earth.
Source: [Dev.to](https://dev.to/furiosastudio/eclipse-mechanics-for-programmers-turning-ephemeris-data-into-a-next-eclipse-from-here-countdown-2dbp)