Benchmark: Date.now() vs new Date().getTime() vs performance.now() with calc function

Script Preparation code:

var timestamp = null;

function t1 () {
  timestamp = Date.now() - Date.now();
} 

function t2 () {
  timestamp = new Date().getTime() - new Date().getTime();
} 

function t3 () {
  timestamp = performance.now() - performance.now();
}

Tests:

Date.now()
t1();
new Date().getTime();
t2();
performance.now()
t3();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Date.now()
new Date().getTime();
performance.now()

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Overview**

The provided benchmark compares three different methods to get the current timestamp: `Date.now()`, `new Date().getTime()`, and `performance.now()`.

**Methods Comparison**

1. **`Date.now()`**: This method returns the number of milliseconds since the Unix epoch (January 1, 1970, 00:00:00 UTC). It's a simple and straightforward way to get the current timestamp.
	* Pros:
		+ Fastest execution time
		+ Widely supported across browsers and platforms
	* Cons:
		+ May not be as precise as other methods (e.g., due to system clock resolution)
2. **`new Date().getTime()`**: This method creates a new `Date` object and returns the number of milliseconds since the Unix epoch. It's similar to `Date.now()`, but creates an additional object.
	* Pros:
		+ May be more precise than `Date.now()` due to its own clock resolution
	* Cons:
		+ Slower execution time compared to `Date.now()`
3. **`performance.now()`**: This method returns the number of milliseconds since the performance timer started (usually when the page loads). It's designed for high-precision timing and is often used in benchmarking and testing.
	* Pros:
		+ Highly precise timing
		+ Suitable for long-running tests or benchmarks
	* Cons:
		+ May not be suitable for very short intervals due to its own clock resolution

**Library Use**

None of the provided methods use external libraries. However, `Date` and `performance` are built-in JavaScript objects that provide these timing functions.

**Special JS Features**

No special JavaScript features (e.g., async/await, Promises, ES6 classes) are used in this benchmark.

**Other Alternatives**

If you need to compare other methods for getting the current timestamp, some alternatives include:

* `Date.now()`: Returns the number of milliseconds since the Unix epoch.
* `new Date().getTime()`: Creates a new `Date` object and returns its timestamp.
* `performance.now()`: Returns the number of milliseconds since the performance timer started.

These methods can be used in various contexts, such as:

* Creating high-precision timers for scientific computing or game development
* Measuring execution times for benchmarking and testing
* Getting the current timestamp for logging or analytics purposes

Note that the choice of method depends on the specific use case and requirements.

Related benchmarks:

Date.now() vs new Date().getTime() vs performance.now() with calc function (version: 0)

Comparing performance of: Date.now() vs new Date().getTime(); vs performance.now()

Created: 3 years ago by: Guest

Jump to the latest result

Date.now()

new Date().getTime();

performance.now()

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):