Benchmark: Date.now() vs new Date().valueOf()

Script Preparation code:

let timestamp = null

Tests:

Date.now()
timestamp = Date.now()
new Date().valueOf()
timestamp = new Date().valueOf()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Date.now()
new Date().valueOf()

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Browser/OS: Chrome 121 on Windows

View result in a separate tab

Test name	Executions per second
Date.now()	2959890.5 Ops/sec
new Date().valueOf()	2575824.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**What is being tested?**

The benchmark is comparing two ways to get the current timestamp in JavaScript: `Date.now()` and `new Date().valueOf()`. The goal is to determine which method is faster, more efficient, or both.

**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). It's a simple and efficient way to get the current timestamp.
2. **`new Date().valueOf()`**: This method returns the number of milliseconds since the Unix epoch, but it's slightly more complex because it creates a new `Date` object and then calls its `valueOf()` method.

**Pros and Cons**

* **`Date.now()`**:
	+ Pros: Fast, simple, and widely supported.
	+ Cons: May not be as precise as other methods (e.g., `performance.now()`) due to system clock resolution limitations.
* **`new Date().valueOf()`**:
	+ Pros: More accurate than `Date.now()` because it creates a new date object with the current timestamp, which can help reduce jitter and noise in the result.
	+ Cons: Slightly slower and more complex than `Date.now()`.

**Library/Features used**

* **`Date` object**: This is a built-in JavaScript object that represents a specific point in time. The `Date.now()` method uses this object to get the current timestamp.
* **`performance.now()`**: Although not explicitly mentioned, it's worth noting that `performance.now()` also returns the number of milliseconds since the Unix epoch and is often used for high-performance timing measurements. However, its presence is not required in this specific benchmark.

**Special JS feature**

None of the code snippets use any special JavaScript features or syntax.

**Other alternatives**

If you want to compare other methods for getting the current timestamp in JavaScript, some alternative approaches include:

* **`new Date().getTime()`**: Similar to `new Date().valueOf()`, but uses the `getTime()` method instead.
* **`performance.now()`**: As mentioned earlier, this method returns the number of milliseconds since the Unix epoch and is often used for high-performance timing measurements.
* **`Date.now()` with some optimizations**: Some browsers and JavaScript engines offer optimization options for `Date.now()`, such as using a cached timestamp or reducing the resolution.

Keep in mind that these alternatives might not be part of the standard JavaScript API, and their usage may require specific browser or engine support.

Related benchmarks:

Date.now() vs new Date().valueOf() (version: 0)

Comparing performance of: Date.now() vs new Date().valueOf()

Created: 3 years ago by: Guest

Jump to the latest result

Date.now()

new Date().valueOf()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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