Benchmark: Eval ISO vs Epoch

Script Preparation code:

var timestamp = null;

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Windows

View result in a separate tab

Test name	Executions per second
new Date().toISOString()	2085118.2 Ops/sec
Date.now();	12119328.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to explain what's being tested in the provided benchmark.

**Benchmark Definition**

The benchmark definition is a JSON object that defines the characteristics of the test. It contains two relevant parts:

1. `Script Preparation Code`: This is a snippet of JavaScript code that is executed before running the actual test. In this case, it initializes a variable `timestamp` to either `null`, `new Date().toISOString()`, or `Date.now()`.
2. `Html Preparation Code`: This is not used in this benchmark, as it's empty.

**Options being compared**

The two options being compared are:

1. **Using `Date.now()`**: This function returns the number of milliseconds since the Unix epoch (January 1, 1970, 00:00:00 UTC).
2. **Using `new Date().toISOString()`**: This expression creates a new Date object and returns its string representation in ISO format (YYYY-MM-DDTHH:mm:ss.sssZ).

**Pros and Cons of each approach**

**Using `Date.now()`:**

Pros:

* Faster execution time, as it's a simple arithmetic operation.
* More accurate for measuring time intervals, as it provides nanosecond resolution.

Cons:

* May not be suitable for tests that require a specific date or timestamp.
* Can produce inconsistent results due to various factors like system clock drift.

**Using `new Date().toISOString()`:**

Pros:

* Provides a more human-readable and consistent date representation.
* Can be useful in tests where a specific date format is required.

Cons:

* Slower execution time, as it involves creating a new Date object and formatting its string representation.
* May not provide the same level of precision as `Date.now()`.

**Library usage**

In this benchmark, the `Date` library is used. The `Date` class provides a way to represent dates and times in JavaScript. It's a built-in object and doesn't require any external libraries or dependencies.

**Special JS feature or syntax**

The benchmark uses a modern JavaScript feature called "template literals" (introduced in ECMAScript 2015). Template literals allow you to embed expressions inside string literals using the `${}` syntax. In this case, `new Date().toISOString()` is used as a template literal.

**Other alternatives**

For measuring time intervals, other approaches could be:

* Using a timing library like `ms` or `performance.now()`.
* Creating a custom timer function.
* Utilizing Web Workers for concurrent execution.

However, in this specific benchmark, the comparison between `Date.now()` and `new Date().toISOString()` seems to be focused on understanding the performance difference between these two approaches.

Related benchmarks:

Eval ISO vs Epoch (version: 0)

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

Created: 2 years ago by: Guest

Jump to the latest result

new Date().toISOString()

Date.now();

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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