package org.kuali.ole.deliver.calendar.service;
   
   import freemarker.template.SimpleDate;
   import org.kuali.rice.core.api.util.RiceConstants;
   
   import java.sql.Timestamp;
   import java.text.DateFormat;
   import java.text.ParseException;
   import java.text.SimpleDateFormat;
  import java.util.Calendar;
  import java.util.Date;
  
  
  /**
   * Created with IntelliJ IDEA.
   * User: vivekb
   * Date: 7/25/13
   * Time: 5:20 PM
   * To change this template use File | Settings | File Templates.
   */
  public class DateUtil {
  
      private SimpleDateFormat simpleDateFormat;
  
      public static Timestamp addDays(Timestamp date, int days) {
          Calendar cal = Calendar.getInstance();
          cal.setTime(date);
          cal.add(Calendar.DATE, days); //minus number would decrement the days
          return new Timestamp(cal.getTime().getTime());
  
  
      }
  
      public static Timestamp addHours(Timestamp date, int numOfHours) {          //changed
  
          Long milliSecInAnHour = new Long(60 * 60 * 1000);
          Timestamp newTS = new Timestamp(date.getTime());
          long milliSecToAdd = milliSecInAnHour * numOfHours;
          long newTimeMilliSec = newTS.getTime();
          newTS.setTime(newTimeMilliSec + milliSecToAdd);
          return newTS;
  
  
      }//end addHours method..
  
      // Replace with KK:mma if you want 0-11 interval
      private static final DateFormat TWELVE_TF = new SimpleDateFormat("hh:mma");
      // Replace with kk:mm if you want 1-24 interval
      private static final DateFormat TWENTY_FOUR_TF = new SimpleDateFormat("HH:mm");
  
      public static String convertTo24HoursFormat(String twelveHourTime)
              throws ParseException {
          return TWENTY_FOUR_TF.format(
                  TWELVE_TF.parse(twelveHourTime));
      }
  
      public static String convertTo12HoursFormat(String twentyFourHourTime)
              throws ParseException {
          return TWELVE_TF.format(
                  TWENTY_FOUR_TF.parse(twentyFourHourTime));
      }
  
  
      public Date getDate(String dateString) {
          SimpleDateFormat dateFormat = getDateFormat();
          try {
              return dateFormat.parse(dateString);
          } catch (ParseException e) {
              e.printStackTrace();
          }
          return  null;
      }
  
      private SimpleDateFormat getDateFormat() {
          if(simpleDateFormat == null){
              simpleDateFormat = new SimpleDateFormat(RiceConstants.SIMPLE_DATE_FORMAT_FOR_DATE);
          }
          return simpleDateFormat;
      }
  
      public void setSimpleDateFormat(SimpleDateFormat simpleDateFormat) {
          this.simpleDateFormat = simpleDateFormat;
      }
  }