Benchmark: new Date().getTime() vs Date.parse()

Tests:

new Date().getTime()
new Date('2023-08-12T05:12:15.500Z').getTime();
Date.parse()
Date.parse('2023-08-12T05:12:15.500Z')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new Date().getTime()
Date.parse()

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**What is being tested?**

The provided JSON represents a benchmark that compares two approaches for measuring time: `new Date().getTime()` and `Date.parse()`. Specifically, it measures the execution speed of these two methods when creating a new `Date` object with a specific date string.

**Options compared:**

1. **`new Date().getTime()`**: This method returns the number of milliseconds since the Unix epoch (January 1, 1970, 00:00:00 UTC) when the `Date` object is created. It's a relatively simple and widely supported approach.
2. **`Date.parse()`**: This method parses a date string in the format `YYYY-MM-DDTHH:mm:ss.sssZ` (e.g., "2023-08-12T05:12:15.500Z") into a Unix timestamp. It's more complex than `getTime()`, as it requires parsing a specific date format.

**Pros and cons of each approach:**

1. **`new Date().getTime()`**:
	* Pros:
		+ Simple to implement
		+ Fast execution (typically)
	* Cons:
		+ May not work well with dates before the Unix epoch (1970-01-01 00:00:00 UTC)
		+ Can be affected by system clock resolution and other factors
2. **`Date.parse()`**:
	* Pros:
		+ Works with dates from any point in time
		+ Less dependent on system clock resolution
	* Cons:
		+ More complex to implement due to the need for date parsing
		+ May be slower than `getTime()`

**Library and purpose:**

The benchmark does not use a specific JavaScript library. However, it's worth noting that `Date` objects are built-in and widely supported in most modern browsers.

**Special JS feature or syntax:**

This benchmark uses the `Z` character in the date string to indicate UTC time zone. This is a standard practice for representing dates in the ISO 8601 format.

**Other considerations:**

* The benchmark results show that `Date.parse()` consistently outperforms `new Date().getTime()`, likely due to its reduced dependence on system clock resolution.
* The use of desktop and Mac OS X 10.15 as the device platform might affect the results, as these platforms have specific hardware and software characteristics that can impact performance.

**Alternatives:**

If you're looking for alternative approaches to measuring time in JavaScript, consider:

1. **`Performance.now()`**: A more modern approach that returns the number of milliseconds since the performance counter was started.
2. **`Date.now()`**: Similar to `getTime()`, but may be faster due to its optimized implementation.
3. **`setTimeout()` with a very short timeout**: Another approach that relies on the timer resolution of the browser, which might vary depending on the device and platform.

Keep in mind that these alternatives might have their own trade-offs and may not always outperform the tested approaches.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/116.0

Browser/OS: Firefox 116 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
new Date().getTime()	7897956.5 Ops/sec
Date.parse()	13219737.0 Ops/sec

Related benchmarks:

new Date().getTime() vs Date.parse() (version: 0)

Comparing performance of: new Date().getTime() vs Date.parse()

Created: one year ago by: Guest

Jump to the latest result

new Date().getTime()

Date.parse()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):