dateConstructorClones

Prefer passing a Date directly to the Date constructor when cloning, rather than calling getTime().

✅ This rule is included in the ts logical preset.

The Date constructor can clone a Date object directly when passed as an argument. Calling .getTime() first is unnecessary since ES2015.

Before ES2015, new Date(date) converted the date to a string first, making it unreliable for cloning. Modern JavaScript runtimes pass the date value directly, making the .getTime() call redundant.

Examples

❌ Incorrect

const original = new Date();
const clone = new Date(original.getTime());

function cloneDate(date: Date) {
  return new Date(date.getTime());
}

✅ Correct

const original = new Date();
const clone = new Date(original);

function cloneDate(date: Date) {
  return new Date(date);
}

Options

This rule is not configurable.

When Not To Use It

If your codebase needs to support pre-ES2015 environments where new Date(date) behavior was unreliable, or if you have manually changed global aspects of Date such as the .getTime() method, you may need to disable this rule. However, most modern codebases target ES2015 or later and can use the direct approach.

Further Reading

• MDN documentation on Date constructor
• MDN documentation on Date.prototype.getTime()

Equivalents in Other Linters

• ESLint: unicorn/consistent-date-clone