Benchmark: Date valueOf() vs Date.now()

Tests:

valueOf()
return new Date().valueOf()
now()
return Date.now()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
valueOf()
now()

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:131.0) Gecko/20100101 Firefox/131.0

Browser/OS: Firefox 131 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
valueOf()	9944037.0 Ops/sec
now()	13070891.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to help explain the provided benchmark.

**Benchmark Definition and Preparation Code**

The provided JSON represents a simple JavaScript benchmark that tests two different ways to get the current timestamp: using `Date.now()` or by converting a new Date object to its `valueOf()` method. The script preparation code is empty, which means it doesn't perform any initialization or setup before running the benchmarks.

**Options Compared**

There are only two options being compared:

1. **`Date.now()`**: This method returns the number of milliseconds since the Unix epoch (January 1, 1970) as an integer.
2. **`new Date().valueOf()`**: This method converts a new Date object to its `valueOf()` method, which also returns the number of milliseconds since the Unix epoch as an integer.

**Pros and Cons**

*   **`Date.now()`**:
    *   Pros: It is generally faster than `new Date().valueOf()`, as it doesn't involve creating a new Date object.
    *   Cons: It may be slower on older browsers or systems that don't support the `Date.now()` method. Additionally, some libraries might override this method with their own implementation.
*   **`new Date().valueOf()`**:
    *   Pros: This approach avoids using built-in methods or variables that might be overridden by other libraries or extensions. It's also more explicit about what it does.
    *   Cons: As mentioned earlier, it can be slower than `Date.now()`, and some browsers or systems might not support it.

**Library Usage**

There is no library being used in this benchmark. The only JavaScript method being tested is the built-in `Date` object's `now()` method for comparison with its own `valueOf()` method.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntaxes being tested in this benchmark. It's a simple microbenchmark that tests two different ways to get the current timestamp using the standard `Date` object.

**Other Considerations**

*   When running benchmarks, it's essential to consider factors like system load, network traffic, and browser versions that might impact performance.
*   This benchmark only measures execution speed; other factors like memory usage or cache hits may also be relevant in certain scenarios.
*   The benchmark results provided are for a specific Chrome 103 build on a Mac OS X 10.15.7 system.

**Alternatives**

If you need to create similar benchmarks, consider the following alternatives:

1.  **Benchmarking frameworks**: Libraries like Benchmark.js or js-benchmark provide more comprehensive features for writing and running benchmarks.
2.  **Other timing functions**: You might want to test other methods for getting the current timestamp, such as `Date.now()`'s alternative implementations (e.g., WebKit's `webkitTimeSinceHighResolution()`) or even external libraries like Moment.js.
3.  **Edge cases and error handling**: Consider adding edge case scenarios (e.g., invalid date inputs) or error handling to make the benchmark more comprehensive.

Remember, benchmarking can be complex, especially when considering various factors that might impact performance.

Related benchmarks:

Date valueOf() vs Date.now() (version: 0)

Comparing performance of: valueOf() vs now()

Created: 2 years ago by: Guest

Jump to the latest result

valueOf()

now()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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