Klokwerk is a utility library that improves developer experience when working with JS Date objects. The library features chainable setters, dynamic getters and immutability.

The library exposes a single class DateTime, which is shaped after the native JS Date interface. DateTime reimplements the native Date constructor and its methods in a way that improves developer experience.

let oneYearFromNow = new DateTime().setYear((current) => current.fullYear + 1);

you can construct a new date object just like you are used to do with Date. It essentially works the same as the native JS Date interface.

import { DateTime } from "klokwerk";

new DateTime(); // date from current time
new DateTime("2022-02-18"); // date from string
new DateTime(2022, 1, 18); // date from parameters
new DateTime(1645201589942); // date from time
new DateTime(new Date()); // date from Date
new DateTime(new DateTime()); // date from other DateTime object

You can use the same setter methods as the native Date interface. However, there are some differences.

You can use the current date state as reference to update a property:

let myDate = new DateTime();

// increment by one month
myDate.setMonth((current) => current.month + 1);

DateTime's are immutabe: Its setter methods return a new DateTime instance with updated properties.

let myDate = new DateTime();
let otherDate = myDate.setYear(2022);

myDate === otherDate; // false

Since every setter/setX method returns a new DateTime instance, you can chain these methods.

let myDate = new DateTime().setYear(1993).setMonth(2).setDate(20);

DateTime implements dynamic getters, which mirror JS' Date getter methods. For example, a native Date has the method getFullYear(). The DateTime equivalent is simply fullYear.

let year = new DateTime().fullYear;

You can access the native date object by referencing .native.

new DateTime().native; // Date

DateTime implements valueOf, and behaves like native Date.prototype.valueOf

let time = +new DateTime(); // number

DateTime returns an ISO string

let iso = new DateTime().toString(); // ISO format string