Обсуждение: Extracting date from epoche

Hi I have some data  that is  supose to be  a date but in ecpoche format. How can I reonvert  it to data format. <br
/>Thanksin advance for help. <br />Regards, <pre>-- 
 
Najm Hashmi
Tel:514-271-9791
www.mondo-live.com
www.flipr.com</pre>  

----- Original Message -----
From: "Najm Hashmi" <najm@flipr.com>
To: "pgsql" <pgsql-sql@postgresql.org>
Sent: Tuesday, June 19, 2001 4:46 PM
Subject: [SQL] Extracting date from epoche


> Hi I have some data  that is  supose to be  a date but in ecpoche
> format. How can I reonvert  it to data format.
> Thanks in advance for help.
> Regards,

Something like:

select '1970-01-01 00:00:00+00'::timestamp   + (3600::text || ' seconds')::interval;

should work (3600 is your offset, the 1970 assumes std unix epoch start).
Keep an eye on timezone issues.

Example:

richardh=> select 'epoch'::date + (3600::text || ' seconds')::interval;       ?column?
------------------------1970-01-01 01:00:00+01
(1 row)

richardh=> select '1970-01-01 00:00:00+00'::timestamp + (3600::text || '
seconds')::interval;       ?column?
------------------------1970-01-01 02:00:00+01
(1 row)

The difference is because I am currently in timezone +01 and 'epoch' seems
to assume my timezone. In the second example I explicitly set the timezone.


Tom - I thought 'epoch'::timestamp should work too - good reason, or just
One Of Those Things (tm)?

- Richard Huxton

"Richard Huxton" <dev@archonet.com> writes:
> Tom - I thought 'epoch'::timestamp should work too - good reason, or just
> One Of Those Things (tm)?

It works --- it's a symbolic value, though.

regression=# select 'epoch'::timestamp;?column?
----------epoch
(1 row)

regression=# select 'epoch'::timestamp + ('1 day'::interval);       ?column?
------------------------1970-01-01 19:00:00-05
(1 row)

Note the epoch is midnight GMT = 7pm local time here.
        regards, tom lane

From: "Tom Lane" <tgl@sss.pgh.pa.us>

> "Richard Huxton" <dev@archonet.com> writes:
> > Tom - I thought 'epoch'::timestamp should work too - good reason, or
just
> > One Of Those Things (tm)?
>
> It works --- it's a symbolic value, though.
>
> regression=# select 'epoch'::timestamp;
>  ?column?
> ----------
>  epoch
> (1 row)
>
> regression=# select 'epoch'::timestamp + ('1 day'::interval);
>         ?column?
> ------------------------
>  1970-01-01 19:00:00-05
> (1 row)

Ah - problem is in my wetware then. That's ok.

- Richard Huxton