Java - Calculate Date Frequency

I needed to calculate the biweekly, monthly, or quarterly date frequency and create a list of dates. It's easy using Joda Time.


Here is my Java class. Just pass the start date and end date to the method.

package org.inewsnet.service;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.joda.time.LocalDate;
import org.joda.time.Period;

/**
 * Methods to calculate biweekly, monthly, and quarterly date  frequencies
 * @author Richard Golebiowski
 *
 */
public class DateTimeService {
    /**
     * Calculates the dates for the Biweekly frequency
     * @param dtStart  the tart date
     * @param dtEnd    the end date
     * @return         a list of dates
     */
    public List<Date> getBiwekly(Date dtStart, Date dtEnd){
        List <Date> lstDate = new ArrayList<Date>();
        LocalDate start = new LocalDate(dtStart);
        LocalDate end = new LocalDate(dtEnd);
        Period period = Period.weeks(2);
        Period current = Period.ZERO;
        while (true) {
            LocalDate candidate = start.plus(current);
            if (candidate.isEqual(end) || candidate.isAfter(end)) {
                lstDate.add(dtEnd); 
                return lstDate;
            }
            else {
                lstDate.add(candidate.toDate());      
            }
            current = current.plus(period);
        }
    }
    
    /**
     * Calculates the dates for the Monthly frequency
     * @param dtStart  the tart date
     * @param dtEnd    the end date
     * @return         a list of dates
     */
    public List<Date> getMonthly(Date dtStart, Date dtEnd){
        List <Date> lstDate = new ArrayList<Date>();
        LocalDate start = new LocalDate(dtStart);
        LocalDate end = new LocalDate(dtEnd);
        Period period = Period.months(1);
        Period current = Period.ZERO;
        while (true) {
            LocalDate candidate = start.plus(current);
            if (candidate.isEqual(end) || candidate.isAfter(end)) {
                lstDate.add(dtEnd); 
                return lstDate;
            }
            else {
                lstDate.add(candidate.toDate());                
            }
            current = current.plus(period);
        }
    }

    /**
     * Calculates the dates for the Quarterly frequency
     * @param dtStart  the tart date
     * @param dtEnd    the end date
     * @return         a list of dates
     */
    public List<Date> getQuarterly(Date dtStart, Date dtEnd){
        List <Date> lstDate = new ArrayList<Date>();
        LocalDate start = new LocalDate(dtStart);
        LocalDate end = new LocalDate(dtEnd);
        Period period = Period.weeks(13);
        Period current = Period.ZERO;
        while (true) {
            LocalDate candidate = start.plus(current);
            if (candidate.isEqual(end) || candidate.isAfter(end)) {
                lstDate.add(dtEnd); 
                return lstDate;
            }
            else {
                lstDate.add(candidate.toDate());                
            }
            current = current.plus(period);
        }
    }
     
}