Excluding weekends from aging calculation/metric

Hi All,
1st scenario:
We are trying to create an attribute which calculates the aging of a ticket.

IF (VALUE(Tickets) <= 60*24) 
   THEN  "1 day" 
ELIF (VALUE(Tickets)>60*24 AND VALUE(Tickets) <= 60*24*2)     
   THEN  "2 days" 
ELIF  (VALUE(Tickets)>60*24*2 AND VALUE(Tickets)<= 60*24*3)    
   THEN "3 days" 
ELIF  (VALUE(Tickets)>60*24*3 AND VALUE(Tickets)<= 60*24*4)    
   THEN "4 days" 
ELIF  (VALUE(Tickets) > 60*24*4)     
   THEN   ">4 days"

ENDIF

but here we want to exclude the weekends and that should not be calculated in aging days.

2nd scenario:

We have created the custom attribute (transferred date) and we are trying to achieve agent work time, when a ticket was transferred to another group/agent how much the current group/agent's exact work time on the same ticket.