Data Wont Return - sql

Question

I have added a timestamp statement to the below SQL but it is not adding it to the table.
with cx(seq, user_id, mod_date_time, menu_optn_name) as (
select 1, 'U1', timestamp '2007-05-21 16:00:00', 'O1' from dual),
cc(seq, user_id, mod_date_time, menu_optn_name) as (
select seq, user_id, cast(mod_date_time as date), menu_optn_name from cx)
select
user_id, MENU_OPTN_NAME, MOD_DATE_TIME,
case
when MOD_DATE_TIME > prior MOD_DATE_TIME+(1/96) and user_id = prior user_id then round((MOD_DATE_TIME - prior MOD_DATE_TIME)*1440,2)
else null
end as TIME_GAP
from
(select
ptt.user_id, MENU_OPTN_NAME, ptt.MOD_DATE_TIME,
row_number() over (partition by ptt.user_id order by ptt.MOD_DATE_TIME) seq
from PROD_TRKG_TRAN ptt
join cd_master cm on
ptt.cd_master_id = cm.cd_master_id
Where
MENU_OPTN_NAME = 'Cycle Cnt {Reserve}' --CHANGE BASED ON WHAT YOUR TRACKING... MENU NAMES AT THE BOTTOM
and ptt.user_id = 'SCOUNCIL' --CHANGE BASED ON WHO YOU WANT TO TRACK FOR A GAP...
and cm.cd_master_id =
(select cd_master_id
from cd_master
where
co = '&CO'
and div = '&DIV')
and ptt.create_date_time >=
/*Today*/ trunc(sysdate)
--/*This Week*/ trunc(sysdate-(to_char(sysdate,'D')-1))
--/*This Month*/ trunc(sysdate)-(to_char(sysdate,'DD')-1)
--/*Date Range*/ '&FromDate' and ptt.create_date_time-1 < '&ToDate'
--group by ptt.user_id
)cc
CONNECT BY
user_id = prior user_id
and seq = prior seq+1
start with
seq = 1
I have the query to show me anything with a time gap greater then 15 will tell me how long the gap is but I want it to account for the start time of the shift being 4PM so if they start work at 4pm and don't do anything in the system until 4:41PM then there was a 41 min gap.
not sure what I did wrong... I built the timestamp part separate and then put it into the query possibly its not meant to go with a query and should be on its own.
Thanks for any insight with this issue.