changing of timezone

[Rick James]

What, if anything, might fail in these cases:

* Master and Slave are both set to "System" timezone, but the systems 
have different timezones.

* Master and Slave are both set to a specific timezone, say PDT, but the 
systems have different timezones.

* Master is Pacific time; slave is UTC.  Pacific time switched yesterday 
due to DST.  (Replication hung on duplicate key; trying to trace it back 
to timezone issues.  PT slaves did not hang.)

* Upgrade machines (Master, Slaves) one at a time -- either changing 
system timezone or changing MySQL timezone.  Or must they be done 
simultaneously.


Correct?

*  DATETIME and DATE values in tables will be totally unaffected by 
changes to timezone settings in OS or MySQL.

*  TIMESTAMP values on disk are _not_ affected by OS/MySQL changes 
(assuming one switches correctly).

*  INSERT/SELECT of TIMESTAMP columns _will_ return different values 
before versus after OS/MySQL change to timezone setting.