Invalid Input syntax for type bigint

hello everyone,

I am trying to run the proc below but get an error : invalid input
syntax for type bigint: "2004-10-26" Can anyone suggest what I am
doing wrong here?

Rx

-- Function: public.getdateallocated(date, date)

DROP FUNCTION public.getdateallocated(date, date);

CREATE OR REPLACE FUNCTION public.getdateallocated(date, date)
RETURNS text AS
'Declare

workflow_t ix_workflow_task%ROWTYPE;

BEGIN

SELECT ix_workflow_task."DATE_COMPLETED",
ix_workflow_task."WORKFLOW_ACTIVITY_XPDL_ID", ix_workflow_task."TYPE"
INTO workflow_t from ix_workflow_task
INNER JOIN ix_workflow_instance ON
ix_workflow_task."WORKFLOW_INSTANCE_KEY" =
ix_workflow_instance."WORKFLOW_INSTANCE_KEY"
INNER JOIN ix_workflow_instance_to_domain ON
ix_workflow_instance_to_domain."WORKFLOW_INSTANCE_KEY" =
ix_workflow_instance."WORKFLOW_INSTANCE_KEY"
INNER JOIN ix_core_case ON
ix_workflow_instance_to_domain."DOMAIN_KEY" =
ix_core_case."CORECASEKEY"
where to_char(ix_workflow_task."DATE_COMPLETED", \'DD-MM-YYYY\') <> \'\'
AND ix_core_case."DELETED" = 0
AND ("CORECASEKEY" in (select * FROM getStatusSwitch($1,$2,
\'Assessment\', \'Prosecution\'))
OR "CORECASEKEY" in (select * from
getStatusSwitch($1,$2, \'Assessment\', \'Investigation\'))
OR "CORECASEKEY" in (select * from
getStatusSwitch($1,$2, \'Assessment\', \'Other\')))
group by ix_workflow_task."DATE_COMPLETED",
ix_workflow_task."WORKFLOW_ACTIVITY_XPDL_ID", ix_workflow_task."TYPE"
having (lower(ix_workflow_task."WORKFLOW_ACTIVITY_XPDL_ID") LIKE
\'organise surveillance - 9b\' AND ix_workflow_task."TYPE" = \'Human\'
or lower(ix_workflow_task."WORKFLOW_ACTIVITY_XPDL_ID")
LIKE \'start case mix workflow - 9\' AND ix_workflow_task."TYPE" =
\'System\'
or lower(ix_workflow_task."WORKFLOW_ACTIVITY_XPDL_ID") LIKE
\'finalise case - 13\' AND ix_workflow_task."TYPE" = \'Human\'
or lower(ix_workflow_task."WORKFLOW_ACTIVITY_XPDL_ID") LIKE
\'complete final priority smart form - 39\' AND
ix_workflow_task."TYPE" = \'Human\'
or lower(ix_workflow_task."WORKFLOW_ACTIVITY_XPDL_ID") LIKE
\'check for case mix type - 17\' AND ix_workflow_task."TYPE" =
\'System\')
and (ix_workflow_task."DATE_COMPLETED" >= $1 and
ix_workflow_task."DATE_COMPLETED" <= $2);

return workflow_t."WORKFLOW_ACTIVITY_XPDL_ID" ||
to_char(workflow_t."DATE_COMPLETED", \'DD-MM-YYYY\');

END;

'
LANGUAGE 'plpgsql' VOLATILE;

select getdateallocated('10/10/04','12/12/04');