输出示例：
right/UTC Tue Jun 30 23:59:60 2015 UT = Tue Jun 30 23:59:60 2015 UTC isdst=0 gmtoff=0 right/UTC Wed Jul 1 00:00:00 2015 UT = Wed Jul 1 00:00:00 2015 UTC isdst=0 gmtoff=0
23:59:60 – 是当前tzdata数据库中最后一个闰秒的条目.
