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

Script Preparation code:

var timestamp = null;

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 14 days ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_1_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.1.1 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 18 on iOS 18.1.1

View result in a separate tab

Test name	Executions per second
timestamp = Date.now();	38783464.0 Ops/sec
timestamp = new Date().toISOString();	6416779.5 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll explain what's being tested on the provided JSON, compare options, and provide pros and cons of each approach.

**What is being tested?**

The benchmark is comparing two approaches to measure time:

1. `Date.now()`: This method returns the number of milliseconds since the Unix Epoch (January 1, 1970) at the moment it was called.
2. `new Date().toISOString()` : This method creates a new Date object and returns its timestamp as a string in ISO format.

**Options compared**

The two options being tested are:

* Option A: `Date.now()`
	+ Pros:
		- Faster execution time, since it doesn't create an additional object or convert the result to a string.
		- Less overhead due to the creation of a new Date object and the conversion to ISO format.
	+ Cons:
		- Returns milliseconds instead of seconds
* Option B: `new Date().toISOString()`
	+ Pros:
		- Returns seconds as an integer, which might be more intuitive for some users.
	+ Cons:
		- Slower execution time due to the creation of a new Date object and the conversion to ISO format.

**Other considerations**

When choosing between these two options, consider the following factors:

* Performance: If speed is critical, `Date.now()` is likely a better choice. However, if readability and precision are more important, `new Date().toISOString()` might be preferred.
* Code simplicity: `Date.now()` requires only one method call, while `new Date().toISOString()` involves two steps (creating a new Date object and converting it to ISO format).
* Library usage: Both options use the built-in JavaScript `Date` object, which is widely supported.

**Library**

The library being used here is JavaScript's built-in `Date` object. The `Date` object provides a way to represent dates and times in a platform-independent manner, making it a fundamental part of most programming languages, including JavaScript.

**Special JS feature**

There isn't a specific special JavaScript feature or syntax being tested here. Both options use standard JavaScript features: the `Date` object and basic arithmetic operations.

**Other alternatives**

Some alternative approaches to measuring time in JavaScript include:

* Using a dedicated timing library like `performance.now()` (introduced in ECMAScript 2015) or `PerformanceObserver`.
* Using a custom timer function, such as a simple interval-based approach.
* Using a third-party library like `ms-performance` or `fastest-execution-time`.

These alternatives might offer better performance, more precise timing, or other features depending on your specific use case.

Related benchmarks:

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

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

Created: 2 years ago by: Guest

Jump to the latest result

timestamp = Date.now();

timestamp = new Date().toISOString();

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):