Local Time Convert To UTC Time In Hive

Question

I searched a lot on Internet but couldn\'t find the answer. Here is my question:

I\'m writing some queries in Hive. I have a UTC timestamp and would like to change i

Answer 1

As far as I can tell, from_utc_timestamp() needs a date string argument, like "2014-01-15 11:21:15", not a unix seconds-since-epoch value. That might be why it is giving odd results when you pass an integer?

The only Hive function that deals with epoch seconds seems to be from_unixtime() which gives you a timestamp string in the server timezone, which I found in /etc/sysconfig/clock - "America/Montreal" in my case.

So you can get a UTC timestamp string via to_utc_timestamp(from_unixtime(1389802875),'America/Montreal'), and then convert to your target timezone with from_utc_timestamp()

It all seems very torturous, particularly having to wire your server TZ into your SQL. Life would be easier if there was a from_unixtime_utc() function or something.

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Update: from_utc_timestamp() does deal with a milliseconds argument as well as a string, but then gets the conversion wrong.

When I try from_utc_timestamp(1389802875000, 'America/Los_Angeles') it gives "2014-01-15 03:21:15" which is wrong.
The correct answer is "2014-01-15 08:21:15" which you can get (for a server in Montreal) via from_utc_timestamp(to_utc_timestamp(from_unixtime(1389802875),'America/Montreal'), 'America/Los_Angeles')