问几个关于日期的问题

Question

Calendar calendar=Calendar.getInstance();
int day=calendar.get(Calendar.DAY_OF_WEEK);
//问题1
System.out.println(day-1);
calendar.set(Calendar.HOUR,0);
calendar.set(Calendar.MINUTE,0);
calendar.set(Calendar.SECOND,0);
calendar.set(Calendar.MILLISECOND,0);Date now=calendar.getTime();
//问题2
System.out.println(now);calendar.set(Calendar.DAY_OF_WEEK,Calendar.SUNDAY);
Date before=calendar.getTime();
//问题3
System.out.println(before);

Answer 1

经验证
第三种方法有问题
还请继续——