java 每日、月、季度的开始时间和结束时间

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

public class Test {

public static void main(String[] args) throws Exception {

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Calendar now = Calendar.getInstance();
        Calendar startDate = new GregorianCalendar();//开始时间
        Calendar endDate = new GregorianCalendar();//结束时间
        int minDay = now.getActualMinimum(Calendar.DAY_OF_MONTH);
        int maxDay = now.getActualMaximum(Calendar.DAY_OF_MONTH);
        //时段，一小时为一个时段
        startDate.set(Calendar.MINUTE, 0);
        startDate.set(Calendar.SECOND, 0);
        System.out.println("当前时段开始时间:"+sdf.format(startDate.getTime()));
        endDate.set(Calendar.MINUTE, 59);
        endDate.set(Calendar.SECOND, 59);
        System.out.println("当前时段结束时间:"+sdf.format(endDate.getTime()));
       
        // 当天开始时间
        startDate.set(Calendar.HOUR_OF_DAY, 0);
        startDate.set(Calendar.MINUTE, 0);
        startDate.set(Calendar.SECOND, 0);
        System.out.println("当天开始时间:"+sdf.format(startDate.getTime()));
       
        //当天结束时间
        endDate.set(Calendar.HOUR_OF_DAY, 23);
        endDate.set(Calendar.MINUTE, 59);
        endDate.set(Calendar.SECOND, 59);
        System.out.println("当天结束时间:"+sdf.format(endDate.getTime()));
       
        // 当周开始时间
        startDate.setFirstDayOfWeek(Calendar.MONDAY);
        startDate.set(Calendar.HOUR_OF_DAY, 0);
        startDate.set(Calendar.MINUTE, 0);
        startDate.set(Calendar.SECOND, 0);
        startDate.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
        System.out.println("当周开始时间:"+sdf.format(startDate.getTime()));
       
        //当周结束时间
        endDate.setFirstDayOfWeek(Calendar.MONDAY);
        endDate.set(Calendar.HOUR_OF_DAY, 23);
        endDate.set(Calendar.MINUTE, 59);
        endDate.set(Calendar.SECOND, 59);
        endDate.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
        System.out.println("当周结束时间:"+sdf.format(endDate.getTime()));
       
        System.out.println("%%%%%%%%%%%%%%%%%%%%%%%%%%%%%");
        now.set(now.get(Calendar.YEAR), now.get(Calendar.MONTH), minDay, 00, 00, 00);
        System.out.println("当月的第一天：" + sdf.format(now.getTime()));
        System.out.println("maxDay:"+maxDay+"Calendar.DAY_OF_MONTH:"+Calendar.DAY_OF_MONTH);
        //按你的要求设置时间
        now.set(now.get(Calendar.YEAR), now.get(Calendar.MONTH), maxDay, 23, 59, 59);
        System.out.println("当月的最后一天：" + sdf.format(now.getTime()));
        System.out.println("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
       
        System.out.println("-----------------------");
        System.out.println(sdf.format(now.getTime()));
        int month = now.get(Calendar.MONTH) + 1;
        if(month == 1 || month ==2 || month ==3){
            now.set(now.get(Calendar.YEAR), 0, minDay, 00, 00, 00);
            System.out.println("一季度的第一天：" + sdf.format(now.getTime()));
            now.set(now.get(Calendar.YEAR), 2, maxDay, 23, 59, 59);
            System.out.println("一季度的最后一天：" + sdf.format(now.getTime()));
        }
        else if(month == 4 || month ==5 || month ==6){
        now.set(now.get(Calendar.YEAR), 3, minDay, 00, 00, 00);
            System.out.println("二季度的第一天：" + sdf.format(now.getTime()));
            now.set(now.get(Calendar.YEAR), 5, maxDay, 23, 59, 59);
            System.out.println("二季度的最后一天：" + sdf.format(now.getTime()));
        }
        else if(month == 7 || month ==8 || month ==9){
        now.set(now.get(Calendar.YEAR), 6, minDay, 00, 00, 00);
            System.out.println("三季度的第一天：" + sdf.format(now.getTime()));
            now.set(now.get(Calendar.YEAR), 8, maxDay, 23, 59, 59);
            System.out.println("三季度的最后一天：" + sdf.format(now.getTime()));
        }
        else if(month == 10 || month ==11 || month ==12){
        now.set(now.get(Calendar.YEAR), 9, minDay, 00, 00, 00);
            System.out.println("四季度的第一天：" + sdf.format(now.getTime()));
            now.set(now.get(Calendar.YEAR), 11, maxDay, 23, 59, 59);
            System.out.println("四季度的最后一天：" + sdf.format(now.getTime()));
        }
       
    }