Format a Calculated Field

I have two date and time fields that I would like to find the time between
them in days/hours/minutes excluding holidays and weekends.

I currently have a code CalcWorkDays but it only gives me DAYS which is good
for one occurence but the user needs to track when an issue was received and
how long it took to acknowledge the issue in days/hours/minutes.

TAT stands for Turnaround Time. I have a Holiday table that lists all the
holidays in our company and excludes holidays and weekends

Acknowledgement TAT: CalcWorkDays([DateTimeReceived],[DateTimeAcknowledged])

Can my code be altered or do I need something else. I researched so much
stuff and I am confused. I read a lot about DateDiff - can this be want I
want? Can it exclude weekends and holidays?

Thanks