Thread

1. When DST occurs

   Justin Clift <aa2@bigpond.net.au> — 2001-05-01T05:36:24Z

   Hi all,
   
   I'm trying to figure out how DST change times will affect a running database?
   
   For example, if I'm running a PostgreSQL 7.1 server through a DST changeover 
   period, how does the database handle this?
   
   Apparently linux automatically does some kind of update during the changeover 
   period, but does that transfer through to PostgreSQL?
   
   Or would the database need to be re-started?
   
   Or <etc> ?
   
   Need to find out this info, but the documentation doesn't appear to mention 
   anything about it, and the mailing list stuff I've read just directly talk 
   about this.
   
   Regards and best wishes,
   
   Justin Clift
   
   

2. Re: When DST occurs

   Doug McNaught <doug@wireboard.com> — 2001-05-04T21:47:39Z

   Justin Clift <aa2@bigpond.net.au> writes:
   
   > Hi all,
   > 
   > I'm trying to figure out how DST change times will affect a running database?
   > 
   > For example, if I'm running a PostgreSQL 7.1 server through a DST changeover 
   > period, how does the database handle this?
   > 
   > Apparently linux automatically does some kind of update during the changeover 
   > period, but does that transfer through to PostgreSQL?
   
   Linux (and Unix in general) and PostgreSQL both store times in UTC,
   which is independent of timezones and DST.  The C library translates
   UTC into a local printable time, taking timezone and DST into account
   as needed.  So things "just work" and you don't usually have to do
   anything special for the DST changeover. 
   
   -Doug
   -- 
   The rain man gave me two cures; he said jump right in,
   The first was Texas medicine--the second was just railroad gin,
   And like a fool I mixed them, and it strangled up my mind,
   Now people just get uglier, and I got no sense of time...          --Dylan
   
   

3. Re: When DST occurs

   Tom Lane <tgl@sss.pgh.pa.us> — 2001-05-04T23:03:53Z

   Justin Clift <aa2@bigpond.net.au> writes:
   > I'm trying to figure out how DST change times will affect a running database?
   
   The usual theory in Unix-based software is to keep everything in GMT
   internally, so the data isn't affected at all by timezone changes.
   Timezone just affects display of timestamp values.
   
   			regards, tom lane