Re: Convert interval to hours

On 09/14/2018 11:10 AM, Steven Lembark wrote:
> On Fri, 14 Sep 2018 11:55:18 -0400
> Peter Kleiner <runtfan71(at)gmail(dot)com> wrote:
>> On Fri, Sep 14, 2018 at 11:51 AM David Gauthier
>> <davegauthierpg(at)gmail(dot)com> wrote:
>>> Hi:
>>>
>>> In perl/DBI, I have code that's getting me an "age" which returns
>>> something like... "-17 days -08:29:35". How can I convert that to
>>> a number of hours (as a float I would presume) ?
> Suggest using one of the date modules. One issue is that not all
> days are 86400s long: "leap second" is used to keep atomic clocks
> in sync with siderial time so that telescopes report consistent
> values over time. Catch is that simply dividing by 3600 doesn't
> always work if the times fall across the wrong days.

Can you give us a hard example of when this won't work?

select extract(epoch from '-17 days -08:29:35'::interval)/3600 as hours;

hours
-------------------
-416.493055555556
(1 row)

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