Benchmark: Date.now() vs new Date().getTime() vs +new Date()

Script Preparation code:

var timestamp = null;

Tests:

Date.now()
timestamp = Date.now();
new Date().getTime();
timestamp = new Date().getTime();
+new Date()
timestamp = +new Date()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.36 Edg/144.0.0.0

Browser/OS: Chrome 144 on Windows

View result in a separate tab

Test name	Executions per second
Date.now()	2442871.5 Ops/sec
new Date().getTime();	2091735.8 Ops/sec
+new Date()	1760063.5 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark, hosted on MeasureThat.net, aims to compare the performance of three different methods for obtaining the current timestamp in JavaScript: `Date.now()`, `new Date().getTime()`, and `+new Date()`.

**Test Cases**

There are three test cases:

1. **`Date.now()`**: This method uses the built-in `Date.now()` function to get the number of milliseconds since the Unix epoch (January 1, 1970).
2. **`new Date().getTime()`**: This method creates a new `Date` object and calls its `getTime()` method to get the timestamp in milliseconds.
3. **`+new Date()`**: This method uses the unary plus operator (`+`) to convert the result of calling `new Date()` to an integer, which is equivalent to getting the timestamp in milliseconds.

**Options Compared**

The benchmark compares the performance of these three methods across different executions per second (e.g., 9495372.0, 8859815.0, and 6899383.0).

**Pros and Cons**

* **`Date.now()`**:
	+ Pros: Simple, efficient, and widely supported.
	+ Cons: May not work correctly in older browsers or environments that don't support modern JavaScript features.
* **`new Date().getTime()`**:
	+ Pros: More flexible than `Date.now()`, as it allows for more customization of the date object (e.g., setting specific time zones).
	+ Cons: Requires creating a new `Date` object, which can be slower and use more memory than using `Date.now()` directly.
* **`+new Date()`**:
	+ Pros: Similar to `new Date().getTime()`, but with less overhead due to the unary plus operator.
	+ Cons: May not work correctly in older browsers or environments that don't support modern JavaScript features.

**Library and Special JS Features**

There are no libraries mentioned in this benchmark. However, it's worth noting that MeasureThat.net uses a custom implementation for executing JavaScript benchmarks on different browsers and platforms.

The benchmark does use modern JavaScript features, such as the `let` keyword ( implicit block scoping) and template literals (string interpolation).

**Other Alternatives**

If you need to compare timestamp methods in other programming languages or environments, consider using alternative implementations:

* For Python: `time.time()` or `datetime.datetime.now()`.
* For Java: `System.currentTimeMillis()` or `java.util.Date()`.
* For C/C++: `time(NULL)` or `gettimeofday()`.
* For Node.js (in addition to JavaScript): `performance.now()`.

Keep in mind that the performance characteristics of different timestamp methods may vary depending on the specific use case, platform, and browser.

Related benchmarks:

Date.now() vs new Date().getTime() vs +new Date() (version: 0)

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

Created: 5 years ago by: Guest

Jump to the latest result

Date.now()

new Date().getTime();

+new Date()

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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