Re: BUG #16338: casting interval '24h' to time returns '00:00:00' instead of '24:00:00'

The following bug has been logged on the website:

Bug reference: 16338
Logged by: Io Mihai
Email address: iomihai(at)hotmail(dot)com
PostgreSQL version: 12.2
Operating system: Arch Linux, Ubntu
Description:

While casting intervals to time I noticed interval '24h' casts to '00:00:00'
time rather than '24:00:00'
Casting first to text or varchar then to time works as expected
select (interval '24h')::time; => '00:00:00'
select (interval '24h')::text::time => '24:00:00';
I experienced this in PostgreSQL 9 -12 .
Is this a bug or is this how it is supposed to work?

Thank you,
Mihai

PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> While casting intervals to time I noticed interval '24h' casts to '00:00:00'
> time rather than '24:00:00'
> Casting first to text or varchar then to time works as expected
> select (interval '24h')::time; => '00:00:00'
> select (interval '24h')::text::time => '24:00:00';
> I experienced this in PostgreSQL 9 -12 .
> Is this a bug or is this how it is supposed to work?

Interval-to-time casts take the interval modulo 24 hours, so I'd
say this is expected.

regression=# select '40:00:01'::interval::time;
time
----------
16:00:01
(1 row)

Note that time itself would refuse to store a value larger than 24hr.

regards, tom lane