timestamp convert to date

Hi List !

I'm running "PostgreSQL 8.3.10 on i486-pc-linux-gnu, compiled by GCC
gcc-4.3.real (Ubuntu 4.3.3-5ubuntu4) 4.3.3" (Ubuntu 9.04)

I want to use -infinity,infinity as my date interval maximum endpoints in an
application I'm writing .
Is it possible to use date ?
I did a test but it looks like date doesn't support infinity as a value.
However this looks like it doesn't give an error either:

select 'infinity'::timestamp::date;

it just gives me a blank row in pgadmin3 query window.
So is infinity supposed to work with date or should this conversion give an
error ?

It would be really nice with the possibility to use infinity with the date
type.

Regards
//Dan