exclude sunday's and time should start from 8.00Am to 6.00PM in mysql query

I have query problem for the below point, So can some help us on this, as we are trying this one for the past 2 weeks.

exclude sunday's and time should start from 8.00Am to 6.00PM in mysql query

And The query we have is

SELECT B.ProblemID, A.problemID,A.EnclID as A_ENCLID,
B.EnclID as B_EnclID, B.EnclSubmittedTime,
(SPLIT_STR(B.enclname,"_", 1)),
B.EnclComment,B.EnclSubmittedTime,
COALESCE((TIMEDIFF(A.EnclSubmittedTime, B.EnclSubmittedTime))) AS Time_DIFF
FROM TABLE B
LEFT JOIN TABLE A ON B.EnclID < A.EnclID
AND A.problemID = B.ProblemID
and A.enclname not like 'Enclosure%'
where B.enclname not like 'Enclosure%'
and A.EnclSubmittedTime not in (
Give_Me_Dates_Days(1, B.EnclSubmittedTime, A.EnclSubmittedTime)
)
Group by B.ProblemID, B.EnclID
order by B.ProblemID ASC

If any quries, please reply to this, we will response you.

Thanks In Advance.