Benchmark: Create Date - MeasureThat.net

Script Preparation code:

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

Tests:

New
var new1 = new Date(start) new1.setHours(0,0,0,0); new1 = new1.getTime();
Reuse
temp1.setTime(start.getTime()); temp1.setHours(0,0,0,0); var new1 = temp1.getTime();
Now Hour set
var new1 = new Date(start) //new1.setHours(0,0,0,0); new1 = new1.getTime() % (1000*60*60*24);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
New
Reuse
Now Hour set

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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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 for measuring the performance of creating dates in different ways. The benchmark compares three approaches:

1. Creating a new date object from scratch (`New`)
2. Reusing an existing date object's `getTime()` method to create a new date object (`Reuse`)
3. Setting the hour component of an existing date object to 0 and then getting its timestamp modulo a large number (`Now Hour set`)

**Benchmark Definitions**

Let's break down each benchmark definition:

* **New**: Creates a new date object from scratch using `new Date()`. The script then sets the hours, minutes, seconds, and milliseconds components of this new date object to 0 and gets its timestamp in milliseconds using `getTime()`.
* **Reuse**: Uses an existing date object's `getTime()` method to create a new date object. The script first creates a date object (`temp1`) and stores its initial value in `start`. It then sets the hour component of this date object to 0 and gets its timestamp modulo a large number using `getTime()`.
* **Now Hour set**: Similar to the previous approach, but without setting the hour component explicitly. Instead, it uses the modulo operator (`%`) to cap the timestamp at the start of the day.

**Options Compared**

The benchmark compares three approaches:

**Pros and Cons**

Here are some pros and cons for each approach:

* **New**:
	+ Pros: Simple and straightforward way to create a new date object.
	+ Cons: May incur additional overhead due to creating a new object on the heap.
* **Reuse**:
	+ Pros: Reuses an existing object, reducing memory allocation and deallocation overhead.
	+ Cons: Requires careful handling of the `getTime()` method's return value, which can be negative or zero.
* **Now Hour set**:
	+ Pros: Similar performance to `Reuse`, but with less code and fewer potential issues.
	+ Cons: May require additional checks for overflow when using modulo arithmetic.

**Libraries and Special JS Features**

There are no libraries used in this benchmark, as it only relies on built-in JavaScript features.

**Other Considerations**

* **Memory Safety**: The `Reuse` approach requires careful handling of the `getTime()` method's return value to avoid potential memory corruption or overflow issues.
* **Arithmetic Performance**: The `Now Hour set` approach uses modulo arithmetic, which can be slower than simple division or multiplication operations. However, in this case, the modulo operation is likely to be performed at compile-time rather than runtime.

**Alternatives**

If you're interested in exploring other approaches, here are a few alternatives:

* **Use a library like Date.js**: This library provides optimized date manipulation functions and may offer better performance than built-in JavaScript methods.
* **Experiment with V8 or SpiderMonkey engines**: These two popular JavaScript engines have different optimizations and might provide varying performance characteristics for this benchmark.

Related benchmarks:

Create Date (version: 0)

Comparing performance of: New vs Reuse vs Now Hour set

Created: 9 years ago by: Guest

Jump to the latest result

New

Reuse

Now Hour set

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):