Re: What does Time.MAX_VALUE actually represent?

From: Gavin Flower <GavinFlower(at)archidevsys(dot)co(dot)nz>
To: pgsql-hackers(at)lists(dot)postgresql(dot)org
Subject: Re: What does Time.MAX_VALUE actually represent?
Date: 2018-01-01 19:54:25
Message-ID: 0d155670-5b95-a066-fd70-1f9ba49df6e5@archidevsys.co.nz
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On 01/02/2018 01:26 AM, Tels wrote:
> Moin,
>
> On Sat, December 30, 2017 4:25 pm, Gavin Flower wrote:
>> On 12/31/2017 03:07 AM, Dave Cramer wrote:
>>> We are having a discussion on the jdbc project about dealing with
>>> 24:00:00.
>>>
>>> https://github.com/pgjdbc/pgjdbc/pull/992#issuecomment-354507612
>>>
>>> Dave Cramer
>> In Dublin (I was there 2001 to 2004), Time tables show buses just after
>> midnight, such as 1:20am as running at the time 2520 - so there are
>> visible close to the end of the day.  If you are looking for buses
>> around midnight this is very user friendly - better than looking at the
>> other end of the time table for 0120.
>>
>> I think logically that 24:00:00 is exactly one day later than 00:00:00 -
>> but I see from following the URL, that there are other complications...
> Careful here, if "24:00:00" always means literally "00:00:00 one day
> later", that could work, but you can't just have it meaning "add 24 hours
> to the clock".
>
> For instance, during daylight saving time changes, days can be 23 hours or
> 25 hours long...
>
> Best wishes,
>
> Tels

Agreed, I'm thinking purely of displayed time.  Where the utility of
using times like 2400 and 2530 is purely the convenience of people
looking to catching a bus after a late night out.

The 24:00 time should be referred to in a similar way to the notation of
'0+' in limits (that is informally defined as the smallest positive real
number -- formally that is nonsense, 'lim 0+' actually means approach
the limit from the positive direction).

Cheers,
Gavin

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