This benchmark on MeasureThat.net compares the performance of two methods for calculating the time difference in JavaScript:

• Date.now(): This method returns the number of milliseconds that have elapsed since the Unix epoch (January 1, 1970, 00:00:00 UTC).
• new Date().getTime(): This creates a new Date object and then uses its .getTime() method to get the number of milliseconds since the Unix epoch.

Breakdown:

The benchmark code essentially performs these actions in both test cases:

1. Creates a variable: timedif = null; is used to store the calculated time difference.
2. Performs the calculation:
   • Test case 1: timedif = Date.now() - Date.now(); This calculates the difference between the current time and itself, always resulting in 0.
   • Test case 2: timedif = new Date() - new Date(); This creates two new Date objects and subtracts their timestamps.

Pros & Cons:

• Date.now():

  • Pros: This method is very efficient as it's a built-in function optimized for performance. It directly returns the milliseconds since the epoch without any additional object creation.
  • Cons: Can be limited if you need more precise time information than milliseconds or require specific date and time formatting.

• new Date().getTime():

  • Pros: Offers more flexibility as it allows access to other Date object methods for manipulating and formatting the timestamp (e.g., getting year, month, day, etc.).
  • Cons: Generally slower than Date.now(), as it involves creating a new Date object and then calling .getTime()

Other Considerations:

This benchmark highlights that Date.now() is significantly faster for simple time difference calculations in JavaScript.

Let me know if you have any more questions about this or other benchmarks!