Benchmark: Date.parse vs new Date vs Date String Split no msec

Script Preparation code:

function getRandomInt(min, max) {
  min = Math.ceil(min);
  max = Math.floor(max);
  return Math.floor(Math.random() * (max - min) + min);
}

Tests:

String split date
var year = getRandomInt(1999,2021); var month = getRandomInt(10,11) var date = getRandomInt(11,28) var hour = getRandomInt(11,23) var minute = getRandomInt(11,59) var b = year + "-" + month + "-" + date + "T" + hour + ":" + minute + ":00.000Z"; var dt = b.substring(0,10).split("-"); var hr = b.substring(11,19).split(":"); Date.UTC(dt[0], --dt[1], dt[2], hr[0], hr[1], hr[2]);
new Date
var year = getRandomInt(1999,2021); var month = getRandomInt(10,11) var date = getRandomInt(11,28) var hour = getRandomInt(11,23) var minute = getRandomInt(11,59) var b = year + "-" + month + "-" + date + "T" + hour + ":" + minute + ":00.000Z"; var genDt= new Date(b)
Date.parse
var year = getRandomInt(1999,2021); var month = getRandomInt(10,11) var date = getRandomInt(11,28) var hour = getRandomInt(11,23) var minute = getRandomInt(11,59) var b = year + "-" + month + "-" + date + "T" + hour + ":" + minute + ":00.000Z"; var genDt= Date.parse(b)
new date from numbers
var year = getRandomInt(1999,2021); var month = getRandomInt(10,11) var date = getRandomInt(11,28) var hour = getRandomInt(11,23) var minute = getRandomInt(11,59) var genDt=new Date(Date.UTC(year, --month, date, hour, minute));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String split date
new Date
Date.parse
new date from numbers

Fastest: N/A

Slowest: N/A

Latest run results:

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

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The provided benchmark measures the performance of three different approaches to parse and create dates in JavaScript:

1. **Date.parse**: This method takes a string as input, parses it into a Date object, and returns the number of milliseconds since the Unix epoch (January 1, 1970, 00:00:00 UTC). In this benchmark, `Date.parse` is used with a date string that has been generated using the `getRandomInt` function.
2. **new Date**: This method takes a string as input, parses it into a Date object, and returns the date value in milliseconds since the Unix epoch. In this benchmark, `new Date` is used with the same date string generated by `getRandomInt`.
3. **Date.UTC** (from numbers): This method takes six arguments: year, month, day, hours, minutes, and milliseconds. It creates a new Date object based on the provided values. In this benchmark, `Date.UTC` is used to create a new Date object from numerical values.

Now, let's discuss the pros and cons of each approach:

**Date.parse**

Pros:

* Simple and concise syntax
* Works well with most date formats

Cons:

* Can be slow due to its parsing algorithm
* May not work correctly for dates that are not in the UTC timezone (e.g., some cultural or historical dates)

**new Date**

Pros:

* Fast and efficient, as it uses a built-in implementation
* Works well with most date formats

Cons:

* Requires an additional string conversion step (using `substring` and `split`)
* May be slower than `Date.UTC` when dealing with large datasets

**Date.UTC** (from numbers)

Pros:

* Fast and efficient, as it avoids string parsing and conversion
* Provides more precise control over date calculations

Cons:

* Requires explicit formatting of the input values
* Can be less intuitive to use for developers without prior experience with `Date.UTC`

The benchmark tests these approaches with a specific date format that is common in modern web development (YYYY-MM-DDTHH:MM:SSZ). The results indicate that **new Date** is the fastest approach, followed by **Date.UTC** from numbers, and then **Date.parse**.

Some notable observations:

* The `String split` test case (`"String split date"`), which manually extracts year, month, day, hours, minutes, and milliseconds from a string using substring and split methods, has the lowest execution rate.
* The results suggest that using numerical values with `Date.UTC` is faster than using strings, which might be due to its more direct implementation.

Other alternatives to these approaches include:

* Using a dedicated date parsing library like Moment.js or Luxon
* Implementing custom date parsing logic using regular expressions or other string manipulation techniques
* Leveraging modern JavaScript features like `Intl.DateTimeFormat` for date formatting and parsing

It's essential to note that the performance differences between these approaches might not be significant in all scenarios, and the choice of method should be based on the specific requirements and constraints of the project.

Related benchmarks:

Date.parse vs new Date vs Date String Split no msec (version: 0)

Comparing performance of: String split date vs new Date vs Date.parse vs new date from numbers

Created: 4 years ago by: Guest

Jump to the latest result

String split date

new Date

Date.parse

new date from numbers

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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