Scripting

I have been working on a goal to have Kace Service Desk ticket reports to display total ticket times from both NEW to OPEN and NEW to CLOSED and I have run accross a problem.  When I use the TIME_TO_SEC function within a monthly report, out of 100 entries, 2 entries show the TIME_TO_SEC of the ticket, CREATED seconds is smaller number than the CLOSED.  I then noticed our times are off when adding up the total times for all the tickets in a month and comparing it to the report.  It gets really weird when I do a cum over several months, one entry which lies outside the criteria thay may show 34 days+.  I am trying to discover whether it is corrupt data or incorrect use of coding.  Here is the code I am working with.

SELECT
(case when
HD_TICKET.CREATED=HD_TICKET.TIME_OPENED then 'All Tickets'
when
HD_TICKET.CREATED<DATE_ADD(IF(HD_TICKET.TIME_OPENED='0',IF(HD_TICKET.TIME_CLOSED='0',0,HD_TICKET.TIME_CLOSED),HD_TICKET.TIME_OPENED),
INTERVAL 1 HOUR) then 'All Tickets'
when
HD_TICKET.CREATED<DATE_ADD(IF(HD_TICKET.TIME_OPENED='0',IF(HD_TICKET.TIME_CLOSED='0',0,HD_TICKET.TIME_CLOSED),HD_TICKET.TIME_OPENED), INTERVAL
24 HOUR) then 'All Tickets'
when
HD_TICKET.CREATED>DATE_ADD(IF(HD_TICKET.TIME_OPENED='0',IF(HD_TICKET.TIME_CLOSED='0',0,HD_TICKET.TIME_CLOSED),HD_TICKET.TIME_OPENED),INTERVAL
24 HOUR) then 'All Tickets'
end ) as CLOSE_GROUP,

count(HD_TICKET.ID) as NUMBER_OF_TICKETS,
CONCAT((sum(TIME_TO_SEC(TIMEDIFF(IF(HD_TICKET.TIME_OPENED='0',IF(HD_TICKET.TIME_CLOSED='0',0,HD_TICKET.TIME_CLOSED),HD_TICKET.TIME_OPENED),HD_TICKET.CREATED)))/count(HD_TICKET.ID)
div 86400),'d ',
TIME_FORMAT(SEC_TO_TIME(sum(TIME_TO_SEC(TIMEDIFF(IF(HD_TICKET.TIME_OPENED='0',IF(HD_TICKET.TIME_CLOSED='0',0,HD_TICKET.TIME_CLOSED),HD_TICKET.TIME_OPENED),HD_TICKET.CREATED)))/count(HD_TICKET.ID) mod 86400 ), '%kh %im %ss')) as AVG_TIME_TO_OPEN from HD_TICKET,HD_STATUS
where
HD_TICKET.HD_STATUS_ID=HD_STATUS.ID
and CREATED>='2014-10-01' /*change the start date here*/
and CREATED<='2014-10-31' /*change the end date here*/
and HD_TICKET.HD_QUEUE_ID in (1) /*add queue numbers here*/
group by CLOSE_GROUP