timestamp out of range while casting return value to function's return type

Hi all

I created a function that ought to return a timestamptz (another
likewise timestamp) but calling it, I get mentionied error. What do I
miss? I tried to return a timestamp of the year 2000 to no avail.

Call: select utils.get_max_timestamptz();
--

Function
--
create or replace function GET_MAX_TIMESTAMPTZ()
returns timestamptz
language plpgsql
immutable
-- Include the hosting schema into search_path so that dblink
-- can find the pglogger objects. There is no need to access
-- objects in other schematas not covered with public.
as
$body$
begin
-- highest timestamps on 64bit lubuntu vanilla PostgreSQL 11.3
return '294277-01-01 00:59:59.999999'::timestamptz;
end;
$body$;

Kind regards

Thiemo

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