[database-devel] UTCTime and Timestamp Without Time Zone

Greg Weber greg at gregweber.info
Mon Jun 4 16:23:33 CEST 2012

There is some work under way for an improved time zone library that
you might be interested in:

On Mon, Jun 4, 2012 at 6:02 AM, Leon Smith <leon.p.smith at gmail.com> wrote:
> Well, I played around with it a little more,  and discovered that the  1883
> Nov 18 behavior is specific to my local time zone.   I think the moral of
> the story is that time is messy and complicated,  and that I should probably
> extend the timezone parser at least a little bit.    Unfortunately GHC's
> time package assumes that time zones are offset by an integer number of
> minutes,  so handling the 3 minute and 58 second offset used in that sample
> case is a bit trickier.   And given that I doubt most people will care about
> timestamps before the 20th century,  I'll probably release without dealing
> with this.
> Then again,  an even better solution would be to get postgresql-simple to
> the point it can send and receive binary values.    By default, PostgreSQL
> 8.4 and newer represents timestamps as 64-bit ints of microseconds before or
> after 2000-01-01 00:00:00+00;  sending and receiving this format would be a
> great deal faster,  and would isolate these types of corner cases to Haskell
> alone,  instead of infecting the interface between PostgreSQL and Haskell.
> Unfortunately,  receiving results in binary is currently an all-or-nothing
> proposition,  which certainly complicates the situation.    It is not so
> easy to selectively receive some columns in binary and the rest in the
> textual format.   You can explicitly cast/convert some columns to text,  but
> then you also change the type OIDs that Haskell sees.   The most convenient
> thing would be able to set a connection-specific variable that controls
> which types are received in binary and which types are not;  but to the best
> of my knowledge,  PostgreSQL has no such thing.
> Best,
> Leon
> On Sun, Jun 3, 2012 at 11:30 AM, Michael Snoyman <michael at snoyman.com>
> wrote:
>> Thanks for the reference to November 18, 1883. That was an interesting
>> read!
>> I agree with your analysis of the situation with types. If this results in
>> the need for breaking changes to persistent-postgresql, so be it. I'd rather
>> have correctness than false stability.
>> I looked at the code a bit, it looks good to me.
>> On Jun 2, 2012 8:40 PM, "Leon Smith" <leon.p.smith at gmail.com> wrote:
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