What calculate ErlangC in Python for callcenter

Question

How to see the need over 30 minute intervals? Already insert a history of the number of calls to make a prediction and on top of this projected demand calculate the erlang?

I'm using this code:

 import pyworkforce
 from pyworkforce.queuing import ErlangC

 erlang = ErlangC(transactions=1000, asa=20/60, aht=3, interval=30, shrinkage=0.3)

 positions_requirements = erlang.required_positions(service_level=0.8, max_occupancy=0.85)
 print("Vagas Requeridas: ", positions_requirements)

But don't show for interval, in graphic or text.

Thanks for help.