Calculating date difference

Here is a quick way to calculate the difference between two dates counted in days.
You can easily modify it to use different TimeUnit.

import java.util.*;
import java.util.concurrent.TimeUnit;

public class Main {
  
  public static int days_diff(Date from, Date to) {
    long time_diff = Math.abs(to.getTime() - from.getTime() );
    int days = (int) TimeUnit.DAYS.convert(time_diff, TimeUnit.MILLISECONDS);
    return days;
  }

  public static void main(String[] args) {
      Date now = new Date();
      //use year - 1900, and month counting starts from Zero
      Date past = new Date(2022 - 1900, 3 - 1,1);
      
      System.out.println("now: " + past);
      System.out.println("now: " + now);
      System.out.println("Days difference : " + days_diff(past,now));
  }
}

-----------------------

now: Tue Mar 01 00:00:00 UTC 2022
now: Wed Mar 23 14:24:54 UTC 2022
Days difference : 22

Tags: datedifference