Date-fns is a popular JavaScript library designed for working with dates and times. It provides a simple and efficient way to manipulate, format, and compare dates without the complexity of native date functions. The library is modular, allowing developers to import only the functions they need, which helps keep applications lightweight. One of the key features of Date-fns is its extensive set of functions that cover a wide range of date-related tasks, such as adding or subtracting time, formatting dates in various styles, and calculating differences between dates. This makes it a valuable tool for developers looking to enhance their applications with robust date handling capabilities.