MySQL-5.6の/var/log/mysqld.logへ出力される時刻の表記にまつわる不思議

MySQL-5.6から、/var/log/mysqld.logへ出力時の時刻表記が代わり、
YYMMDDから、YYYY-MM-DDという形式になりました。
ところが、mysqld_safe Starting mysqld daemon ... の出力だけ古い形式のままでした。

MySQL Bugをあたってみましたが、特に言及はされてなさそうです。
ログを正規表現で取り込んでいる方がいらっしゃれば、ご注意下さい。

比較バージョン

MySQL-5.5.31-2

$ rpm -qa | grep ^MySQL
MySQL-server-5.5.31-2.el6.x86_64
MySQL-client-5.5.31-2.el6.x86_64
MySQL-devel-5.5.31-2.el6.x86_64
MySQL-shared-compat-5.5.31-2.el6.x86_64
MySQL-shared-5.5.31-2.el6.x86_64

MySQL-5.6.11-2

$ rpm -qa | grep ^MySQL
MySQL-server-5.6.11-2.el6.x86_64
MySQL-client-5.6.11-2.el6.x86_64
MySQL-devel-5.6.11-2.el6.x86_64
MySQL-shared-compat-5.6.11-2.el6.x86_64
MySQL-shared-5.6.11-2.el6.x86_64

ログ出力サンプル

MySQL-5.5.31-2 での /var/log/mysqld.log 出力

$ tailf /var/log/mysqld.log
130515 14:29:24 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
130515 14:29:24 [Note] Plugin 'FEDERATED' is disabled.
130515 14:29:24 InnoDB: The InnoDB memory heap is disabled
130515 14:29:24 InnoDB: Mutexes and rw_locks use GCC atomic builtins
130515 14:29:24 InnoDB: Compressed tables use zlib 1.2.3
130515 14:29:24 InnoDB: Using Linux native AIO
130515 14:29:24 InnoDB: Initializing buffer pool, size = 40.0G
130515 14:29:27 InnoDB: Completed initialization of buffer pool
130515 14:29:27 InnoDB: highest supported file format is Barracuda.
130515 14:29:29  InnoDB: Waiting for the background threads to start
130515 14:29:30 InnoDB: 5.5.31 started; log sequence number 1595675
130515 14:29:30 [Note] Server hostname (bind-address): '0.0.0.0'; port: 3306
130515 14:29:30 [Note]   - '0.0.0.0' resolves to '0.0.0.0';
130515 14:29:30 [Note] Server socket created on IP: '0.0.0.0'.
130515 14:29:30 [Note] Event Scheduler: Loaded 0 events
130515 14:29:30 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.5.31-log'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  MySQL Community Server (GPL)

MySQL-5.6.11-2 での /var/log/mysqld.log 出力

$ tailf /var/log/mysqld.log
130515 16:12:25 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
2013-05-15 16:12:25 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2013-05-15 16:12:25 7350 [Note] InnoDB: The InnoDB memory heap is disabled
2013-05-15 16:12:25 7350 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2013-05-15 16:12:25 7350 [Note] InnoDB: Compressed tables use zlib 1.2.3
2013-05-15 16:12:25 7350 [Note] InnoDB: Using Linux native AIO
2013-05-15 16:12:25 7350 [Note] InnoDB: Using CPU crc32 instructions
2013-05-15 16:12:25 7350 [Note] InnoDB: Initializing buffer pool, size = 40.0G
2013-05-15 16:12:27 7350 [Note] InnoDB: Completed initialization of buffer pool
2013-05-15 16:12:27 7350 [Note] InnoDB: Highest supported file format is Barracuda.
2013-05-15 16:12:28 7350 [Note] InnoDB: 128 rollback segment(s) are active.
2013-05-15 16:12:28 7350 [Note] InnoDB: Waiting for purge to start
2013-05-15 16:12:28 7350 [Note] InnoDB: 5.6.11 started; log sequence number 2832870
2013-05-15 16:12:28 7350 [Note] Server hostname (bind-address): '*'; port: 3306
2013-05-15 16:12:28 7350 [Note] IPv6 is not available.
2013-05-15 16:12:28 7350 [Note]   - '0.0.0.0' resolves to '0.0.0.0';
2013-05-15 16:12:28 7350 [Note] Server socket created on IP: '0.0.0.0'.
2013-05-15 16:12:28 7350 [Note] Event Scheduler: Loaded 0 events
2013-05-15 16:12:28 7350 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.6.11-log'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  MySQL Community Server (GPL)