判断上班时间

package check_work;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class CheckIfInWork {

	/**
	 * @author yj
	 * @param args
	 */
	public static void main(String[] args) throws Exception{
		final String state01 = "07：00之后";
		final String state02 = "07：00之前19：00之后";//8:00 -- 20:00
		final String state03 = "19：00之前";//20:00之后
		String str_date = "2010-06-29";//state01的日期
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		Date init_date = sdf.parse(str_date);
		Date today = new Date();
		
		Calendar init_c = Calendar.getInstance();
		init_c.setTime(init_date);
		
		Calendar today_c = Calendar.getInstance();
		today_c.setTime(today);
		
		int day_offset = today_c.get(Calendar.DAY_OF_YEAR)-init_c.get(Calendar.DAY_OF_YEAR);
		
		int i = day_offset%3;
		
		switch(i){
		case 0:
			System.out.println(state01);
			break;
		case 1:
			System.out.println(state02);
			break;
		case 2:
			System.out.println(state03);
		}
	}

}