Help on calculating Duration(HH:MM:SS)

Hi there,

I would be great if anyone help me on below issue:

Table Name: Table1

SCAN_DTTM REPORTED_DTTM
17/12/2013 10:00 27/12/2013 12:00
30/12/2013 09:30 02/01/2014 10:00
18/12/2013 12:00 19/12/2013 16:00
20/12/2013 09:00 20/12/2013 17:00

Table Name:  Date
 
Date            Working Day
17/12/2013      Y
18/12/2013      Y
19/12/2013      Y
20/12/2013      Y
21/12/2013      N
22/12/2013      N
23/12/2013      Y
24/12/2013      Y
25/12/2013      B
26/12/2013      B
27/12/2013      Y
28/12/2013      N
29/12/2013      N
30/12/2013      Y
31/12/2013      Y
01/01/2014      B
02/01/2014      Y
03/01/2014      Y

Information:        
Mon      Tue           Wed          Thu           Fri                          Comments   
09:00                                                         17:30                        Standard week(Mon 09:00 to completion time: 17:30 on Friday)   
09:00    17:30         Holiday      09:00        17:30                         If bank holiday comes(e.g: this week) - 1st Jan 2014 is holiday   
09:00    17:30         Holiday      Holiday      09:00 - 17:30            If bank holiday comes(e.g: last  week) - 25th & 26th Dec' 2013 are holidays   

Expected Out come
 
SCAN_DTTM            REPORTED_DTTM            Duration(HH:MM:SS)
17/12/2013 10:00      27/12/2013 12:00           115:00:00
30/12/2013 09:30      02/01/2014 10:00            33:00:00
18/12/2013 12:00      19/12/2013 16:00            28:00:00
20/12/2013 09:00      20/12/2013 17:00            08:00

Example calucation:  

SCAN_DTTM            REPORTED_DTTM 
30/12/2013 09:30     02/01/2014 10:00 
  
From 30/12/2013 09:30 to 31/12/2013 (until 17:30) 32 hrs
01/01/2014 is Holiday                                               0hrs
02/01/2014    from 09:00 to 10:00 is                        1 Hr
                                                                   Net Total 33Hrs

Thanks&Regards

Mohan