Moment.js, a popular date-handling library, was deprecated by its maintainers in September 2020 due to its essential design not changing despite the rapid development of the JavaScript ecosystem. The library's maintainers prioritized stability over new features, leading to potential breaking changes for millions of projects. Moment is now considered a "legacy project in maintenance mode" with limited support and no new features, discouraging its use in new projects. Its limitations include mutable objects, issues with modern tree shaking algorithms, and less effective date handling compared to modern browsers and implementations. To mitigate these risks, developers should consider using alternative libraries like Luxon, Day.js, or date-fns, which offer improved functionality and maintainability. One developer's experience shows that while the transition from Moment to Day.js was significant, it ultimately led to reduced bundle sizes and a safer codebase.