如何准确设置sqlite时间的报警

Question

这是我的代码，当我在本地数据库中插入时间和日期字符串时，我在本地数据库中插入的时间也设置了警报接收器，但问题是当我插入过去的时间和日期字符串时在数据库中，它将在当前时间触发，而时间已经过去。它适用于最新的时间和日期字符串

Calendar calender = Calendar.getInstance();
                    calender.clear();
                    calender.set(Calendar.MONTH, pickerDate.getMonth());
                    calender.set(Calendar.DAY_OF_MONTH, pickerDate.getDayOfMonth());
                    calender.set(Calendar.YEAR, pickerDate.getYear());
                    calender.set(Calendar.HOUR, pickerTime.getCurrentHour());
                    calender.set(Calendar.MINUTE, pickerTime.getCurrentMinute());
                    calender.set(Calendar.SECOND, 00);
                    SimpleDateFormat formatter = new SimpleDateFormat(getString(R.string.hour_minutes));
                    String timeString = formatter.format(new Date(calender.getTimeInMillis()));
                    SimpleDateFormat dateformatter = new SimpleDateFormat(getString(R.string.dateformate));
                    String dateString = dateformatter.format(new Date(calender.getTimeInMillis()));


                    AlarmManager alarmMgr = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
                    Intent intent = new Intent(getApplicationContext(), AlarmReceiver.class);
                    String alertTitle = mTitleText.getText().toString();
                    intent.putExtra(getString(R.string.alert_title), alertTitle);
              // broadcastCode++;
                    PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), broadcastCode, intent, PendingIntent.FLAG_UPDATE_CURRENT);
                    broadcastCode+=1;
                    alarmMgr.setExact(AlarmManager.RTC_WAKEUP, calender.getTimeInMillis(), pendingIntent);
                    cv.put(mDbHelper.TIME, timeString);
                    cv.put(mDbHelper.DATE, dateString);

                db.insert(mDbHelper.TABLE_NAME, null, cv);