Re: Question about Postgresql time fields(possible bug) - Mailing list pgsql-hackers

From Dave Page
Subject Re: Question about Postgresql time fields(possible bug)
Date
Msg-id E7F85A1B5FF8D44C8A1AF6885BC9A0E40103D685@ratbert.vale-housing.co.uk
Whole thread Raw
In response to Question about Postgresql time fields(possible bug)  (Tony Caduto <tony_caduto@amsoftwaredesign.com>)
List pgsql-hackers

> -----Original Message-----
> From: pgsql-hackers-owner@postgresql.org
> [mailto:pgsql-hackers-owner@postgresql.org] On Behalf Of Harald Fuchs
> Sent: 10 January 2006 16:53
> To: pgsql-hackers@postgresql.org
> Subject: Re: [HACKERS] Question about Postgresql time
> fields(possible bug)
>
> In article <200601101551.k0AFpnK17299@candle.pha.pa.us>,
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
>
> > Tony Caduto wrote:
> >> Hi,
> >> I just noticed today that Postgresql accepts a value of
> 24:00:00, this
> >> is for sure not correct as there is no such thing as 24:00:00
> >>
> >> PG Admin III will display this value just fine which is
> also incorrect,
> >> PG Lightning Admin catches it as a invalid time, but
> shouldn't there be
> >> some validation of times and dates at the server level?
> >>
> >> There are people who are using PG Admin III and they don't
> even know
> >> they have bogus dates and times in their databases.
>
> > A leap second will show as 24:00:00.  It is a valid time.
>
> Shouldn't such a leap second be represented as '... 23:59:60'?

On looking further it appears to me that 24:00:00 is not a leap second
(which definitely can be 23:50:60), but just another way of expressing
midnight.

From: http://www.cl.cam.ac.uk/~mgk25/iso-time.html

--------------
As every day both starts and ends with midnight, the two notations 00:00
and 24:00 are available to distinguish the two midnights that can be
associated with one date. This means that the following two notations
refer to exactly the same point in time:

1995-02-04 24:00 = 1995-02-05 00:00
--------------

So:

postgres=# select ('1995-02-04 24:00'::timestamp = '1995-02-05
00:00'::timestamp);?column?
----------t
(1 row)

Regards, Dave.


pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: Question about Postgresql time fields(possible bug)
Next
From: Harald Fuchs
Date:
Subject: Re: Question about Postgresql time fields(possible bug)