You don't need: MomentJS?

While striving to minimise the footprint of production compiled JS code for some of my side projects, I found this great collection of nice, but sometimes controversial, repositories.

Problems with Moment.js:

It is highly based on OOP APIs, which makes it fail to work with tree-shaking, thus leading to a huge bundle size and performance issues.

It is mutable due to OOP APIs and non-pure functions, which cause bugs like these.