Benchmark: Date.now() vs new Date().toISOString() vs performance.now();

Script Preparation code:

var timestamp = null;

Tests:

timestamp = Date.now();
timestamp = Date.now();
timestamp = new Date().toISOString();
timestamp = new Date().toISOString();
timestamp = performance.now();
timestamp = performance.now();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
timestamp = Date.now();
timestamp = new Date().toISOString();
timestamp = performance.now();

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of MeasureThat.net and explore what's being tested in this benchmark.

**Benchmark Definition**

The provided JSON defines a single benchmark with three variations:

1. `timestamp = Date.now();`
2. `timestamp = new Date().toISOString();`
3. `timestamp = performance.now();`

These three lines are used to measure the execution time of each statement, and their results will be compared.

**Options Compared**

The options being compared are:

* `Date.now()`: Returns the number of milliseconds since the Unix Epoch (January 1, 1970, 00:00:00 UTC) in the current timezone. It's a simple and widely supported method for measuring time.
* `new Date().toISOString()`: Converts the current date and time to a string in ISO 8601 format (`YYYY-MM-DDTHH:mm:ss.SSSZ`). This is a more complex method that includes the timezone, which can affect the result.
* `performance.now()`: Returns the number of milliseconds since the Unix Epoch (January 1, 1970, 00:00:00 UTC) on the current platform. It's designed specifically for measuring time intervals and provides higher precision than `Date.now()`.

**Pros and Cons**

Here's a brief summary of each option:

* `Date.now()`: Pros:
	+ Simple and widely supported.
	+ Fast execution.
	Cons:
	+ May include timezone offset, which can affect results on different platforms.
	+ Lower precision compared to `performance.now()`.
* `new Date().toISOString()`: Pros:
	+ Includes the timezone in the result, making it more accurate for cross-platform comparisons.
	+ More precise than `Date.now()`.
Cons:
	+ More complex and resource-intensive due to the string conversion process.
	+ May be slower than `Date.now()` or `performance.now()` due to the overhead of converting to a string.
* `performance.now()`: Pros:
	+ High precision for measuring time intervals.
	+ Platform-specific optimization for better performance.
Cons:
	+ Not as widely supported as `Date.now()` due to its platform dependence.
	+ May require special handling on certain platforms (e.g., older browsers).

**Library and Special JS Features**

There are no libraries used in this benchmark.

**Special JS Features**

None of the benchmark variations use any special JavaScript features. They only rely on standard ECMAScript syntax and built-in functions.

**Other Alternatives**

If you need to measure time intervals or performance in a JavaScript application, you might consider using other methods, such as:

* `setTimeout()` with a callback function
* `setInterval()`
* Web Workers for parallel processing
* Profiling tools like Chrome DevTools or Node.js Inspector

These alternatives may offer better performance, accuracy, or ease of use depending on your specific requirements.

In conclusion, this benchmark tests the execution time differences between three methods for measuring time: `Date.now()`, `new Date().toISOString()`, and `performance.now()`. The results provide valuable insights into the performance characteristics of each method on a given platform.

Latest run results:

Run details: (Test run date: 7 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36

Browser/OS: Chrome 123 on Windows

View result in a separate tab

Test name	Executions per second
timestamp = Date.now();	4768101.0 Ops/sec
timestamp = new Date().toISOString();	967030.4 Ops/sec
timestamp = performance.now();	3232395.5 Ops/sec

Related benchmarks:

Date.now() vs new Date().toISOString() vs performance.now(); (version: 0)

Comparing performance of: timestamp = Date.now(); vs timestamp = new Date().toISOString(); vs timestamp = performance.now();

Created: 8 months ago by: Guest

Jump to the latest result

timestamp = Date.now();

timestamp = new Date().toISOString();

timestamp = performance.now();

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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