I have a workflow that creates a task where I need to set the due date to be 3 business days prior to custom field date on the transaction. I found this on StackExchange but am not sure how to make this work for my needs:

CASE WHEN INSTR(to_char({custbody_date}, 'DAY'),'SATURDAY') != 0 
THEN {custbody_date}+2 
WHEN INSTR(to_char({custbody_date}, 'DAY'),'SUNDAY') != 0 
THEN {custbody_date}+1 ELSE {custbody_date} 
END

Any ideas?

I would use the following formula in your workflow CASE WHEN TO_CHAR({customtransactiondate} - 3, ‘DD’) = 7 THEN {customtransactiondate} - 5 WHEN TO_CHAR({customtransactiondate} - 3,’DD’) = 6 THEN {customtransactiondate} - 4 ELSE {customtransactiondate} - 3 END