Roll the java.util.Date forward or backward in Java

//from   www . j av  a 2s  . c  o  m
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class Main {

  /**
   * Roll the java.util.Date forward or backward.
   * 
   * @param startDate
   *          - The start date
   * @period Calendar.YEAR etc
   * @param amount
   *          - Negative to rollbackwards.
   */
  public static java.util.Date rollDateTime(java.util.Date startDate,
      int period, int amount) {
    GregorianCalendar gc = new GregorianCalendar();
    gc.setTime(startDate);
    gc.add(period, amount);
    return new java.util.Date(gc.getTime().getTime());
  }

  public static void main(String[] argv) {
    System.out.println(rollDateTime(new Date(), Calendar.MINUTE, 10));
  }
}