Benchmark: new Date from timestamp vs new Date from string

Tests:

new Date timestamp
new Date(1678973400);
new Date string
const str = '2023-03-16' new Date(...str.split('-'))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new Date timestamp
new Date string

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 129 on Android

View result in a separate tab

Test name	Executions per second
new Date timestamp	2543667.5 Ops/sec
new Date string	840153.8 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested.

**Benchmark Purpose:**

The purpose of this benchmark is to compare the performance of two ways to create `Date` objects in JavaScript:

1. Using the `new Date()` constructor with a timestamp (in milliseconds).
2. Using the `new Date()` constructor with a string representation of a date, using the `Date.parse()` method.

**Tested Options:**

There are only two options being compared:

1. **new Date(1678973400);**: This option uses a fixed timestamp to create a new `Date` object.
2. **const str = '2023-03-16'\r\nnew Date(...str.split('-'))\r\n**: This option uses a string representation of a date, split by the hyphen character, and then passes the resulting parts to the `Date()` constructor.

**Pros and Cons:**

**Option 1 (new Date(1678973400);)**

Pros:

* Uses a fixed timestamp, which is likely to be more accurate and consistent.
* Does not require parsing a string date format.

Cons:

* May not account for daylight saving time (DST) adjustments or other timezone-related issues.
* Requires a specific timestamp value, which may change over time.

**Option 2 (const str = '2023-03-16'\r\nnew Date(...str.split('-'))\r\n)**

Pros:

* Can handle date formats with varying levels of precision and separators.
* Does not require a fixed timestamp value.

Cons:

* May be slower due to the string parsing step.
* Requires accurate parsing of the input string date format, which can be error-prone.

**Library Usage:**

None of the test cases use any external libraries.

**Special JS Features/Syntax:**

The benchmark uses the following JavaScript feature:

* **Template literals**: The `const str = '2023-03-16'\r\nnew Date(...str.split('-'))\r\n` syntax is using a template literal to concatenate strings and split dates. This feature is only available in modern browsers that support ECMAScript 2015 (ES6) or later.

**Alternatives:**

Other alternatives for creating `Date` objects include:

* Using the `Date.now()` method, which returns the number of milliseconds since the Unix epoch (January 1, 1970).
* Using a library like Moment.js, which provides a more robust and flexible date parsing and formatting API.
* Using the `Date constructor` with a specific timezone offset or DST adjustment.

Note that these alternatives may have their own trade-offs in terms of performance, accuracy, and compatibility across different browsers and platforms.

Related benchmarks:

new Date from timestamp vs new Date from string (version: 0)

Comparing performance of: new Date timestamp vs new Date string

Created: one year ago by: Guest

Jump to the latest result

new Date timestamp

new Date string

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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