Kasper Rönning <kasper.ronning@reliabit.fi> writes:
> I seem to have found a bug in Postgres 9.1.3. Apparently timestamp
> values are stored correctly in the database, but querying it returns
> invalid results. My environment is Windows 7 64bit. The unexpected
> result is that timestamps before 1st of May 1921 are displayed
> incorrectly when time zone is 'Europe/Helsinki'.
This is not incorrect. The Olson timezone database shows:
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Europe/Helsinki 1:39:52 - LMT 1878 May 31 1:39:52 - HMT 1921 May # Helsinki Mean
Time 2:00 Finland EE%sT 1983 2:00 EU EE%sT
that is, it was only in 1921 that Helsinki adopted "standard" time
referenced to the Greenwich meridian. Before that it would have been
typical to set clocks by local mean solar time, which is 1:39:52 east
of Greenwich.
regards, tom lane