Function Syntax involving pipes and ' marks?

No matter how many times i try, i can't seem to get the write amount of '
marks around the date parameters in my v_where declaration. What am i doing
wrong here?

v_stmt should look like this if done correctly:

select count(distinct m.id)
from (select id, greatest(max(last_p),max(last_b)) as date_created from job
group by id) m where m.jb_date < '2008-08-29' and m.jb >='2008-08-28'.
when instead it's coming out like this:
select count(distinct m.id) from (select id,
greatest(max(last_periodic),max(last_boot)) as date_created from mediaportal
group by id) m where m.date_created < 2008-08-29 and m.date_created
>=2008-08-28 .
...no tick marks around the dates.

here's my code:

CREATE OR REPLACE FUNCTION fcn_job(p_date date,
p_type varchar,
p_jobid numeric)
RETURNS numeric AS $$

DECLARE
v_job numeric := 0;
v_stmt varchar(1024);
v_where varchar(256) := 'where m.jb_date < '||p_date + integer '1'||
' and m.jb_date >='||p_date||'';

BEGIN
v_stmt := fcn_gen_statement(p_type, v_where, p_newonly);
execute v_stmt into v_job;
RAISE NOTICE 'sql looks like this: % . ',v_stmt;
return v_job;
END;
$$ LANGUAGE plpgsql;