How to measure the a time-span in seconds using System.currentTimeMillis()?

Question

How to convert System.currentTimeMillis(); to seconds?

long start6=System.currentTimeMillis();
System.out.println(counter.countPrimes(100000000)         


        

Answer 1

TimeUnit

Use the TimeUnit enum built into Java 5 and later.

long timeMillis = System.currentTimeMillis();
long timeSeconds = TimeUnit.MILLISECONDS.toSeconds(timeMillis);