date-fns is a modern JavaScript date utility library providing a comprehensive suite of functions for manipulating and formatting dates. Designed with modularity and immutability in mind, it allows you to select only the functions you need, reducing bundle size. Unlike Moment.js, date-fns promotes tree-shaking, resulting in smaller and more performant applications. Its API is consistent and well-documented, making it a popular choice for developers seeking a reliable date manipulation solution.