Fast and memory-efficient time zone estimations can be achieved using the @photostructure/tz-lookup package, a fork of the abandoned darkskyapp/tz-lookup. Improvements include a new time zone database, TypeScript types, performance benchmarks, and ongoing maintenance support, with a focus on accuracy and speed compared to the geo-tz library. While the package is significantly smaller and faster, it may produce errors near timezone borders, especially in sparsely populated areas.