Benchmark: Date.now vs new Date

Script Preparation code:

let timestamp = null

Tests:

Date.Now
timestamp = Date.now()
New Date
timestamp = new Date();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Date.Now
New Date

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and explain what is being tested.

**What is being tested?**

The benchmark tests two approaches to get the current timestamp in JavaScript: `Date.now()` and `new Date()`. The goal is to determine which approach is faster.

**Options compared:**

There are two options being compared:

1. **`Date.now()`**: This method returns the number of milliseconds since the Unix Epoch (January 1, 1970, 00:00:00 UTC) as an integer. It's a simple and efficient way to get the current timestamp.
2. **`new Date()`**: This constructor creates a new `Date` object with the current date and time. While it returns a `Date` object, it doesn't provide a direct way to get the timestamp.

**Pros and Cons:**

* **`Date.now()`**:
	+ Pros:
		- Fast and efficient
		- Returns an integer value that can be used directly in calculations or comparisons
	+ Cons:
		- Only available in ECMAScript 2015 (ES6) and later versions
* **`new Date()`**:
	+ Pros:
		- Widespread support across older JavaScript engines and browsers
	+ Cons:
		- Returns a `Date` object, which can be slower to process than an integer value
		- Not suitable for all use cases (e.g., when working with dates and times)

**Other considerations:**

* The benchmark is running in a desktop environment with Chrome 87 on a Mac OS X 10.15.7.
* The `timestamp` variable is initialized to `null` before the test case starts.

**Library and syntax analysis:**

There are no libraries or special JavaScript features mentioned in this benchmark definition.

**Benchmark preparation code:**

The script preparation code creates an empty `timestamp` variable, which will be used to store the current timestamp. The HTML preparation code is not provided, as it's likely that no HTML-related setup is needed for this simple benchmark.

**Other alternatives:**

If you wanted to compare these approaches in a different context or with additional options, some alternative benchmarks could include:

* Comparing `Date.now()` and `new Date()` against other timestamping methods (e.g., `performance.now()`, `requestAnimationFrame`)
* Including more modern JavaScript features (e.g., arrow functions, destructuring) to see their impact on performance
* Adding multiple test cases with different inputs or edge cases to ensure the results are representative of real-world scenarios

Overall, this benchmark provides a good starting point for understanding the differences between `Date.now()` and `new Date()` in JavaScript.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36

Browser/OS: Chrome 87 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Date.Now	2639248.8 Ops/sec
New Date	2325679.5 Ops/sec

Related benchmarks:

Date.now vs new Date (version: 0)

Comparing performance of: Date.Now vs New Date

Created: 3 years ago by: Guest

Jump to the latest result

Date.Now

New Date

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):