So it's a better moment made by the moment team: https://moment.github.io/luxon/docs/manual/faq/moment.html Major differences: * Immutable * Months in Luxon are 1-indexed instead of 0-indexed like in Moment and the native Date type. * Localizations and time zones are implemented by the native Intl API (or a polyfill of it), instead of by the library itself. * Luxon has both a Duration type and an Interval type. The I…
In what situation is immutable important?
I think there are lots of good reasons to make datetimes immutable (e.g. many of the same reasons most languages make strings immutable). But here's one specific to Moment and Luxon: chainable APIs should really always have immutable types because the return value is the thing you use next anyway. When each call returns an instance of the type it's both completely unnecessary and very often harmful for those calls to modify anything.
var a = moment();
console.log("the end of tomorrow is", a.add(1, 'day').endOf('day'));
// do more stuff with a
// oh crap, a is now set to tomorrow? wtf?
var a = moment();
a.add(1, 'day');
a.endOf('day');
// do stuff with a