time difference

 
Hi,

I have a file like below (with more lines) and I want to compare the elapse time beetwen two date and insert the result in a new colum. 
 
My file :
Num ;        Date_1       ; Status_1 ; 	Date_2		; Status_2
14  ; 2012-10-11 18:09:33 ; CONFIRME ; 2012-10-12 12:33:02 	; REJETEE	
15  ; 2012-10-11 18:09:56 ; CONFIRME ; 2012-10-12 18:24:29 	; REJETEE 	
...
...


I would like to have in the result.

Num ; Elapse_time_in_days ;        Date_1       ; Status_1 ; 	Date_2		; Status_2 
14  ;         0           ; 2012-10-11 18:09:33 ; CONFIRME ; 2012-10-12 12:33:02 	; REJETEE  ;	
15  ;        32           ; 2012-10-11 18:09:56 ; CONFIRME ; 2012-11-12 18:24:29 	; REJETEE  ;	
...
...


I can calculate the différence time like below but I don't know how to insert the result in a new colum with sed may be.

date +%s -d "2012-10-11 18:09:33"
1349971773
date +%s -d "2012-10-12 12:33:02"
1350037982
expr \( 1349971773 - 1350037982 \) / 86400
0


date +%s -d "2012-10-11 18:09:56 "
1349971796
date +%s -d "2012-11-12 18:24:29 "
1352741069
expr \( 1352741069 - 1349971796 \) / 86400
32


Many thanks in advance for any help/idea.
Regards.
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