Bug #73240 EXTRACT function with DAY_HOUR does not return the day part.
Submitted: 9 Jul 2014 10:26
Reporter: Shane Bester (Platinum Quality Contributor) Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: Data Types Severity:S3 (Non-critical)
Version:5.6.19 OS:Any
Assigned to: CPU Architecture:Any

[9 Jul 2014 10:26] Shane Bester
Description:
On 5.5:
--------

mysql> select extract(day_hour from now()) a,now(),version();
+------+---------------------+-----------+
| a    | now()               | version() |
+------+---------------------+-----------+
|  912 | 2014-07-09 12:19:20 | 5.5.38    |
+------+---------------------+-----------+
1 row in set (0.06 sec)

On 5.6 and 5.7:
-----------------
mysql> select extract(day_hour from now()) a,now(),version();
+------+---------------------+-----------+
| a    | now()               | version() |
+------+---------------------+-----------+
|   12 | 2014-07-09 12:18:38 | 5.6.19    |
+------+---------------------+-----------+
1 row in set (0.00 sec)

How to repeat:
select extract(day_hour from now()) a,now(),version();
select extract(day_hour from '2014-07-09 12:17:43') a,now(),version();
[9 Jul 2014 10:34] MySQL Verification Team
this broke since 5.6.4.  5.6.3 and 5.5 worked okay.