Hello @tcedarwilson ,
Welcome to the monday community! 
You can use this:
NETWORKDAYS({Date 1 }, {Date 2}, SPLIT({Holidays}, ","))
Where Date 1 is holiday start, Date 2 is holiday end, and Holidays is where the Holidays are listed.
Hope this helps!
Best Regards,
Giannis Implementation Consultant at thespelas.com