Add a number of minutes to a date returning a new object in Java

//  w  w  w. j  a va  2  s  . c  o  m
import java.util.Calendar;
import java.util.Date;

public class Main {
  public static Date addMinutes(Date date, int amount) {
    return add(date, Calendar.MINUTE, amount);
  }

  private static Date add(Date date, int calendarField, int amount) {
    if (date == null) {
      throw new IllegalArgumentException("The date must not be null");
    }
    Calendar c = Calendar.getInstance();
    c.setTime(date);
    c.add(calendarField, amount);
    return c.getTime();
  }

  public static void main(String[] argv) {
    Date date = new Date();

    System.out.println(addMinutes(date, 100));
  }
}