Benchmark: Create Date - MeasureThat.net

Script Preparation code:

var start = new Date();
var temp1 = new Date();

Tests:

new Date
var new1 = new Date(start) new1.setHours(0,0,0,0); new1 = new1.getTime();
setTime
temp1.setTime(start.getTime()); temp1.setHours(0,0,0,0); var new1 = temp1.getTime();
Mod 24 Hours
var new1 = start.getTime() % (1000*60*60*24);
New Date set All
var new1 = new Date(start.getFullYear(), start.getMonth(), start.getDate(), 0, 0, 0, 0);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new Date
setTime
Mod 24 Hours
New Date set All

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what is being tested, compared options, pros and cons of each approach, and other considerations.

**Benchmark Definition**

The benchmark definition json provides the basic information about the test case, including:

* `Name`: The name of the benchmark.
* `Description`: A brief description of the benchmark (in this case, null).
* `Script Preparation Code`: The code that is run before running the actual benchmark. In this case, it sets a reference date `start` to the current date and time using `new Date()`.
* `Html Preparation Code`: Additional HTML preparation code (in this case, none).

**Individual Test Cases**

The test cases are defined in an array of objects, each representing a single test:

1. **`Create Date`**: This is the first test case.
	* `Benchmark Definition`: The actual benchmark code that tests different methods to create a new date object with a specific time.
	* `Test Name`: A descriptive name for the test case.
2. **`setTime`**: The second test case.
3. **`Mod 24 Hours`**: The third test case.
4. **`New Date set All`**: The fourth and final test case.

**What is being tested?**

Each test case compares different methods to create a new date object with a specific time:

1. `new Date(start)`: Creates a new date object using the `start` reference date, but sets it to midnight (00:00:00).
2. `temp1.setTime(start.getTime())`: Sets the internal clock of an existing date object (`temp1`) to the `start` reference date's time.
3. `new Date(start.getFullYear(), start.getMonth(), start.getDate(), 0, 0, 0, 0)`: Creates a new date object using the `start` reference date's year, month, day, hour, minute, second, and millisecond (all set to 0).
4. `var new1 = start.getTime() % (1000*60*60*24)`: Creates a new date object by taking the fractional part of the `start` reference date's time in milliseconds, effectively creating a date that represents the same day but with a different time.

**Options compared**

The test cases compare four different approaches to create a new date object with a specific time:

1. Directly creating a new date object using `new Date()`.
2. Using `setTime()` to set the internal clock of an existing date object.
3. Creating a new date object by extracting the fractional part of the original date's time in milliseconds.
4. Using a more explicit approach with separate parameters for year, month, day, hour, minute, second, and millisecond.

**Pros and Cons of each approach**

Here are some pros and cons of each approach:

1. **Directly creating a new date object using `new Date()`**: Pros: Simple, efficient. Cons: May not be the most accurate due to potential issues with timezone conversion or daylight saving time.
2. **Using `setTime()`**: Pros: More controlled and flexible than direct creation. Cons: Requires an existing date object, which may introduce additional complexity.
3. **Creating a new date object by extracting the fractional part of the original date's time in milliseconds**: Pros: Can be more accurate than direct creation due to avoiding timezone conversion issues. Cons: May not work as expected if the original date's time is not exactly divisible by 1000ms.
4. **Using a more explicit approach with separate parameters for year, month, day, hour, minute, second, and millisecond**: Pros: Highly controlled and flexible. Cons: More verbose and potentially slower due to the need to parse and validate user input.

**Other considerations**

When testing date-related functions in JavaScript, it's essential to consider:

* **Timezone conversion**: Dates are often created with a specific timezone, but may be converted to another timezone when displayed or processed.
* **Daylight saving time (DST)**: DST can affect the creation and display of dates, especially if not properly handled.
* **Fractional seconds**: The precision of date values in JavaScript can lead to issues when dealing with fractional seconds.

**Alternatives**

If you need to test similar benchmark scenarios, consider exploring other approaches, such as:

* Using a different programming language or library that provides better support for date and time manipulation.
* Creating a custom implementation using a combination of JavaScript's built-in functions and additional libraries or frameworks.
* Testing the performance of different JavaScript engines or runtimes.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36

Browser/OS: Chrome 53 on Mac OS X 10.10.3

View result in a separate tab

Test name	Executions per second
new Date	1910056.5 Ops/sec
setTime	1812518.1 Ops/sec
Mod 24 Hours	10133442.0 Ops/sec
New Date set All	1703291.9 Ops/sec

Related benchmarks:

Create Date (version: 0)

Comparing performance of: new Date vs setTime vs Mod 24 Hours vs New Date set All

Created: 8 years ago by: Guest

Jump to the latest result

new Date

setTime

Mod 24 Hours

New Date set All

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):