MySQL dayofyear()函数
DAYOFYEAR(date)
返回年份为日期的天，范围为1至366。
mysql> SELECT DAYOFYEAR('1998-02-03');
+---------------------------------------------------------+
| DAYOFYEAR('1998-02-03') |
+---------------------------------------------------------+
| 34 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
