Benchmark: Intl.DateTimeFormat vs Date().toLocaleString()

Script Preparation code:

var options = {
  year: 'numeric', month: 'numeric', day: 'numeric',
  hour: 'numeric', minute: 'numeric', second: 'numeric',
  hour12: false,
  fractionalSecondDigits: 3,
}

Tests:

Date().toLocaleString
new Date().toLocaleString("en-US", options)
Intl.DateTimeFormat
new Intl.DateTimeFormat('en-US', options).format(new Date())

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Date().toLocaleString
Intl.DateTimeFormat

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36

Browser/OS: Chrome 141 on Mac OS X 10.15.7

View result in a separate tab

Date().toLocaleString

33K/s

Intl.DateTimeFormat

32K/s

View exact numbers

Test name	Executions per second
✓ Date().toLocaleString	33,459 Ops/sec
Intl.DateTimeFormat	31,843 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview of the Benchmark**

The provided JSON represents a JavaScript microbenchmark test case that compares the performance of two methods for formatting dates: `Date().toLocaleString()` and `new Intl.DateTimeFormat('en-US', options).format(new Date())`. The benchmark aims to determine which method is more efficient in terms of execution speed.

**Options Comparison**

The two methods being compared have different approaches to formatting dates:

1. **`Date().toLocaleString()`**: This method uses the `toLocaleString()` method, which is a part of the built-in JavaScript `Date` object. It formats the date based on the user's locale settings and returns a string representation of the date.
2. **`new Intl.DateTimeFormat('en-US', options).format(new Date())`**: This method uses the `Intl.DateTimeFormat()` API, which is part of the Internationalization (i18n) API in JavaScript. It creates an instance of the `DateTimeFormat` class with specific locale settings and formatting options, and then formats a date using the `format()` method.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

* **`Date().toLocaleString()`**:
	+ Pros: Simple to use, widely supported by browsers.
	+ Cons: May not produce consistent results across different locales and devices.
	+ Can be affected by user locale settings.
* **`new Intl.DateTimeFormat('en-US', options).format(new Date())`**:
	+ Pros: Provides more control over formatting options, can produce consistent results across different locales and devices.
	+ Cons: Requires more configuration and setup (locale settings, formatting options), may not be supported by all browsers.

**Library/Api Used**

The `Intl.DateTimeFormat()` API is part of the Internationalization (i18n) API in JavaScript. Its purpose is to provide a standardized way of formatting dates, numbers, and other numeric values based on the user's locale settings.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax used in this benchmark that require additional explanation.

**Other Alternatives**

If you need alternative methods for formatting dates in JavaScript, here are a few options:

1. **`Date.toLocaleString()`**: Similar to `toLocaleString()`, but returns a string representation of the date with an optional locale and options.
2. **`moment.js`**: A popular JavaScript library for working with dates and times that provides more advanced formatting and parsing capabilities.
3. **`dayjs`**: Another popular JavaScript library for working with dates and times that provides more advanced formatting and parsing capabilities.

In summary, the benchmark compares two methods for formatting dates: `Date().toLocaleString()` and `new Intl.DateTimeFormat('en-US', options).format(new Date())`. The first method is simple to use but may not produce consistent results across different locales and devices, while the second method provides more control over formatting options but requires more configuration and setup.

Intl.DateTimeFormat vs Date().toLocaleString() (version: 0)

Comparing performance of: `Date().toLocaleString vs Intl.DateTimeFormat`

Created: 3 years ago by: Registered User

Go to the latest result

Date().toLocaleString

Intl.DateTimeFormat

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Intl.DateTimeFormat vs Date().toLocaleString() (version: 0)

Comparing performance of: Date().toLocaleString vs Intl.DateTimeFormat

Created: 3 years ago by: Registered User

Go to the latest result

Date().toLocaleString

Intl.DateTimeFormat

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

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Comparing performance of: `Date().toLocaleString vs Intl.DateTimeFormat`