#prefer-date-now

#Configuration

import { defineConfig, unicornPlugin } from '@rslint/core';

export default defineConfig([
  unicornPlugin.configs.recommended,
  {
    rules: {
      'unicorn/prefer-date-now': 'error',
    },
  },
]);

#Rule Details

Prefer Date.now() when reading the current timestamp. This avoids creating a Date object only to convert it into the number of milliseconds since the Unix Epoch.

This rule is enabled in the Unicorn recommended preset.

Examples of incorrect code for this rule:

const timestamp = new Date().getTime();
const value = new Date().valueOf();
const number = Number(new Date());
const coerced = +new Date();
const elapsed = new Date() - start;

Examples of correct code for this rule:

const timestamp = Date.now();
const value = Date.now();
const number = Date.now();
const coerced = Date.now();
const elapsed = Date.now() - start;

The rule also checks unary minus, BigInt(new Date()), and the numeric operators -, *, /, %, and **, including their assignment forms. Automatic fixes preserve the surrounding conversion or arithmetic operation.

Only argument-free new Date() expressions are checked. Date construction with arguments, optional method calls, computed method names, addition, and bitwise operations are left unchanged. The rule is syntax-based: a locally declared constructor named Date is treated the same as the built-in.

#Options

This rule has no options.

#Original Documentation

• eslint-plugin-unicorn: prefer-date-now
• Source code