如何只在Android中获取今天的时间戳的calllog日期？

Question

当我使用Cursor使用Cursor获取调用持续时间时，它返回总时间。要获得今天的通话时间，我只会尝试：

  public long getTodayTimestamp(){
        Calendar c1=Calendar.getInstance();
        c1.setTime(new Date());
        Calendar c2=Calendar.getInstance();
        c2.set(Calendar.YEAR, c1.get(Calendar.YEAR));
        c2.set(Calendar.MONTH, c1.get(Calendar.MONTH));
        c2.set(Calendar.DAY_OF_MONTH, c1.get(Calendar.DAY_OF_MONTH));
        c2.set(Calendar.HOUR_OF_DAY, 0);
        c2.set(Calendar.MINUTE, 0);
        c2.set(Calendar.SECOND, 0);
        return c2.getTimeInMillis();
    }

然后这样做：

String timestap=String.valueOf(getTodayTimestamp());
        Cursor managedCursor =managedQuery(CallLog.Calls.CONTENT_URI, null,
                null, null, android.provider.CallLog.Calls.DATE + " DESC");
......

哪个仍然不起作用。如何仅为今天的calllog条目返回时间戳。