Script to work out the Effective Business Days, uses data from Australian Public Holidays Dates Machine Readable Dataset and outputs a csv file. You can use that csv file to upload to Chartio and use the data.
To run it: npm install then node ebd.js and you should see output-ebd.csv generated.
Current script is limited to 3 states (VIC, QLD, NSW) and NAT, but you can change it on line 14.
You may need to change the year in getBusinessDays().