Take Bank Holidays out

Dear all,

how can I count for Bank holidays when counting number of working days under my formula?

I have "Number of days" category in my report and I would like to count only working days, that is Monday to Friday (➖ Weekends and Bank holidays).

I can take the weekends off by using "dayofweek" formula but how can you actually take Bank holidays out?

Using Formula:

if {order_header.order_status}>= 77 then
if dayofweek({order_header.act_despatch})<9 then
1
else
2;
if dayofweek({order_header.act_despatch}) <= 8 then
totext(dayofweek({order_header.act_despatch}),0,'')
else
"9+";

many thanks

Regards

Jehanzeb