Re: BUG #18883: Epoch issue

David G. Johnston <david.g.johnston@gmail.com>

From: "David G. Johnston" <david.g.johnston@gmail.com>

To: "ravi105173@gmail.com" <ravi105173@gmail.com>, "pgsql-bugs@lists.postgresql.org" <pgsql-bugs@lists.postgresql.org>

Date: 2025-04-08T12:29:53Z

Lists: pgsql-bugs

On Tuesday, April 8, 2025, PG Bug reporting form <noreply@postgresql.org>
wrote:

> The following bug has been logged on the website:
>
> Bug reference:      18883
> Logged by:          RAVI KANT BHUSHAN
> Email address:      ravi105173@gmail.com
> PostgreSQL version: 16.1
> Operating system:   Windows 10
> Description:
>
> Number of days calculation using EPOCH is not providing right answer:
>
> Query:      SELECT (EXTRACT(EPOCH FROM ('2025-04-08 11:25:01'::timestamp -
> '2025-03-13 15:33:30'::timestamp)) / 86400)::INT
>                     ==> output is 26, but right answer is 25 days
>
>
select 1.75::int; — yields 2

We don’t document the precise rules for what casting does but rounding
seems reasonable.  Use the floor function to get your expected answer.

David J.