Benchmark: Dayjs Date-fns format comparison

HTML Preparation code:

<script src="https://unpkg.com/dayjs@1.8.21/dayjs.min.js"></script>
<script src="https://igor.moomers.org/random/datefns.js"></script>

Script Preparation code:

window.ds = "2020-02-19T00:51:53.623839+00:00";

Tests:

Date-fns
window.datefns.parseISO(window.ds); window.datefns.format(new Date(), "mm-dd-yyyy");
Dayjs
dayjs(ds) dayjs().format("MM-DD-YYYY")

Historical Performance Data aggregated from 91 community runs

Desktop Results:

Chrome 72 runs

Date-fns

290K/s

Dayjs

263K/s

Fastest: Date-fns (1.1x faster)

View exact numbers

✓ Date-fns: 290,201 ops/sec
• Dayjs: 262,514 ops/sec

Firefox 13 runs

Dayjs

172K/s

Date-fns

129K/s

Fastest: Dayjs (1.3x faster)

View exact numbers

✓ Dayjs: 172,299 ops/sec
• Date-fns: 129,298 ops/sec

Mobile Results:

Chrome 6 runs

Dayjs

175K/s

Date-fns

168K/s

View exact numbers

✓ Dayjs: 174,595 ops/sec
• Date-fns: 168,279 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Date-fns
Dayjs

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36 Edg/148.0.0.0

Browser/OS: Chrome 148 on Windows

View result in a separate tab

Date-fns

267K/s

Dayjs

262K/s

View exact numbers

Test name	Executions per second
✓ Date-fns	266,790 Ops/sec
Dayjs	262,229 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what is being tested, compared, and the pros and cons of each approach.

**Benchmark Test**

The benchmark tests two popular JavaScript libraries for working with dates: Dayjs and Date-fns. The test cases compare the performance of these libraries in parsing an ISO-formatted date string and formatting a new date object using a specific format.

**Options Compared**

The options being compared are:

1. **Date-fns**: A JavaScript library for working with dates, providing various functions for formatting, parsing, and manipulating date values.
2. **Dayjs**: A lightweight JavaScript library for working with dates, similar to Date-fns but with some differences in syntax and functionality.

**Pros and Cons of Each Approach**

Both libraries are designed to perform well in terms of performance, readability, and ease of use. However, here are some pros and cons of each approach:

* **Date-fns**: Pros:
	+ More comprehensive feature set, including support for various date formats, time zones, and parsing rules.
	+ Better support for formatting complex date expressions (e.g., "YYYY-MM-DDTHH:mm:ss.SSSZ").
	+ Easier to extend with custom plugins.
* Cons:
	+ Smaller community compared to Dayjs.
	+ Some users find its syntax more verbose than Dayjs.
* **Dayjs**: Pros:
	+ Simpler and more concise syntax, making it easier to learn and use for beginners.
	+ Faster performance, especially for simple date operations.
	+ Larger community and better support for newer browsers.
* Cons:
	+ Less comprehensive feature set compared to Date-fns.
	+ Limited support for formatting complex date expressions.

**Library Usage**

The test cases use both libraries, with the following code snippets:

1. **Date-fns**: `window.datefns.parseISO(window.ds);` and `window.datefns.format(new Date(), "mm-dd-yyyy");`
2. **Dayjs**: `dayjs(ds)` and `dayjs().format("MM-DD-YYYY")`

**Special JS Feature or Syntax**

Neither library uses any special JavaScript features or syntax beyond standard ES6+ syntax.

**Other Alternatives**

If you're looking for alternative libraries, consider:

1. **Luxon**: A modern JavaScript date library with a simple and consistent API.
2. **Moment.js**: A popular date library with a wide range of features, including internationalization support.
3. **MSTimescale**: A lightweight date library optimized for performance and simplicity.

Keep in mind that each library has its strengths and weaknesses, so it's essential to evaluate your specific needs and choose the best fit for your project.

Dayjs Date-fns format comparison (version: 0)

Comparing performance of: `Date-fns vs Dayjs`

Created: 4 years ago by: Guest

Go to the latest result

Date-fns

Dayjs

Historical Performance Data aggregated from 91 community runs

Desktop Results:

Chrome 72 runs

Firefox 13 runs

Mobile Results:

Chrome 6 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Dayjs Date-fns format comparison (version: 0)

Comparing performance of: Date-fns vs Dayjs

Created: 4 years ago by: Guest

Go to the latest result

Date-fns

Dayjs

Historical Performance Data aggregated from 91 community runs

Desktop Results:

Chrome 72 runs

Firefox 13 runs

Mobile Results:

Chrome 6 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `Date-fns vs Dayjs`