Hi,

I am feeling this topic has been well discussed and the only pending 
issues are below,  it would be great that any committer can have a 
look at these,  so I mark this entry as "Ready for Committer". 

Things are not addressed yet:
1.  the error message handling. 

You can check [1] for more background of this,  I think blocking this
feature at an error message level is not pretty reasonable. 
 
2.  if we have chances to optimize _tz functions, I guess no.
 
patch 002 is dedicated  for this,  I think it should not be committed,
the reason is described in the commit message.

3.  function naming issue. I think I can get it modified once after
all the other issues are addressed. 


[1] https://www.postgresql.org/message-id/d70280648894e56f9f0d12c75090c3d8%40anastigmatix.net 
 
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Best Regards
Andy Fan