KodeGeek

package com.kodegeek.blog.finance;
 
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.HashSet;
import java.util.ResourceBundle;
import java.util.Scanner;
import java.util.Set;
import java.util.logging.Logger;
 
/**
 * Helper date methods tailored for the financial industry.
 * License: LGPL
 * BLOG: http://kodegeek.com
 * @author josevnz@kodegeek.com
 *
 */
public final class DateHelper {
 
	private final static ResourceBundle BUNDLE;
	private final static Logger log;
	private static final Set holidays;
 
	static {
 
		BUNDLE = ResourceBundle.getBundle(DateHelper.class.getName());
 
		log = Logger.getLogger(DateHelper.class.getName());
 
		// Populate the holidays set
		holidays = new HashSet();
		for (String dateStr: BUNDLE.getString("com.kodegeek.blog.finance.DateHelper.holidays").split(";\\s*", -1)) {
			try {
				holidays.add(DateFormat.getDateInstance(DateFormat.DEFAULT).parse(dateStr));
			} catch (ParseException e) {
				log.warning(String.format(BUNDLE.getString("com.kodegeek.blog.finance.DateHelper.error.badDate"), dateStr));
				continue;
			}
		}
 
	}
 
	/**
	 * Default constructor
	 */
	private DateHelper() {
		// Only static methods go on this class
	}
 
	/**
	 * Check if a given date is the last business day of the month
	 * @param aDate The date to test
	 * @return True if is the last day of the month, false otherwise
	 */
	public final static boolean isLastBusinessDayOfMonth(final Date aDate) {
		boolean isLastBusinessDay = false;
 
		// Can do a comparison?
		if (aDate == null) {
			return isLastBusinessDay;
		}
 
		Calendar calendar = Calendar.getInstance();
 
		// Current date on a weekend
		calendar.setTime(aDate);
		int day = calendar.get(Calendar.DAY_OF_MONTH);
		int month = calendar.get(Calendar.MONTH);
		int year =  calendar.get(Calendar.YEAR);
 
		int lastbusinessDayOfMonth = getLastBusinessDayOfMonth(month, year);
		if (lastbusinessDayOfMonth == day) {
			isLastBusinessDay = true;
		}
 
		return isLastBusinessDay;
	}
 
	/**
	 * Get the last business day of the month for a given month / year combination
	 * @param month The month
	 * @param year The year
	 * @return The last business day
	 */
	public static int getLastBusinessDayOfMonth(final int month, final int year) {
		int day = -1;
		Calendar calendar = Calendar.getInstance();
		calendar.set(Calendar.MONTH, month);
		calendar.set(Calendar.YEAR, year);
		calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
 
		// Keep looking backwards until the day is not a weekend or a holiday
		while(true) {
			if (calendar.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY) {
				calendar.add(Calendar.DAY_OF_MONTH, -1);
				continue;
			} else if (calendar.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY) {
				calendar.add(Calendar.DAY_OF_MONTH, -2);
				continue;
			} else if (holidays.contains(calendar.getTime())) {
				calendar.add(Calendar.DAY_OF_MONTH, -1);
				continue;
			}
			break;
		} // End while
		day = calendar.get(Calendar.DAY_OF_MONTH);
		return day;
	}
 
	/**
	 * Unit test, load today date and check if is a end of the month
	 * @param args The date to test from the command line
	 * @throws Exception If the date is invalid for the given local
	 */
	public static void main(String [] args) throws Exception {
		Scanner scan = new Scanner(System.in);
		do {
			String currDateStr = null;
			SimpleDateFormat format = new SimpleDateFormat("yy-M-d");
			try {
				System.out.println("Please enter a date to check (YYYY-MM-DD, Ctrl-C to exit):");
				currDateStr = scan.nextLine();
				Date date = format.parse(currDateStr);
 
				if (date != null) {
					Calendar calendar = Calendar.getInstance();
					calendar.setTime(date);
					int month = calendar.get(Calendar.MONTH);
					int year =  calendar.get(Calendar.YEAR);
					System.out.println(String.format("Last business day of the month: %d", getLastBusinessDayOfMonth(month, year)));
					System.out.println(String.format("%s %s", currDateStr,isLastBusinessDayOfMonth(date) == true? "Is the last business day": "Is not the last business day"));
				}
			} catch (ParseException pExp) {
				System.err.println(String.format("Ignoring bad date: '%s'", currDateStr));
			}
		} while (true);
	}
 
}

# Bank holidays per OCC calendar 2009 - http://www.optionsclearing.com/market/infomemos/2008/oct/24961.pdf
com.kodegeek.blog.finance.DateHelper.holidays=Jan 01, 2009;January 19, 2009; Feb 26, 2009;Apr 10, 2009;May 25, 2009;July 3, 2009; Sep 7, 2009; Nov 26, 2009; Dec 25, 2009; Oct 12, 2009; Nov 11, 2009
com.kodegeek.blog.finance.DateHelper.error.badDate=Got bad date '%s' from property