Oracle conversion of UNIX timestamp to timestamp with time zone

问题

Trying to convert UNIX timestamp to Oracle timestamp with timezone. Expecting to see different output, however datetime part is the same.

What is wring ?

select (timestamp '1970-01-01 00:00:00' + numtodsinterval(1204104116656/1000,'second')) at time zone tz_offset('EST') from dual;

Output: 27-FEB-08 09.21.56.656000000 AM -05:00

select (timestamp '1970-01-01 00:00:00' + numtodsinterval(1204104116656/1000,'second')) at time zone tz_offset('PST') from dual;

Output: 27-FEB-08 09.21.56.656000000 AM -07:00

How come date / time part is the same? Does not Oracle do adjustment ?

回答1:

Unix timestamp is from 1970-01-01 00:00:00 UTC. When you just do timestamp '1970-01-01 00:00:00' Oracle takes your local time zone!

You have to do it like this:

(TIMESTAMP '1970-01-01 00:00:00' AT TIME ZONE 'UTC' +     
    numtodsinterval(1204104116656/1000,'second')) AT time zone tz_offset('PST');

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来源：https://stackoverflow.com/questions/31483658/oracle-conversion-of-unix-timestamp-to-timestamp-with-time-zone