How is Transit Time calculated as a third-party shipping carrier?

[enefege]

How is the Transit time provided by a third-party carrier calculated?

As a Shipping carrier, I couldn´t find any field we provide to shopify that shows the transit time, could it be that Shopify is calculating this field by the max_delivery_date and min_delivery_date fields provided in the shipping rates?

I couldn´t find any information regarding this field in the Shopify documentation.

Also, can this transit time showing the business days in which the order will arrive be hidden in the store admin?

Thank you in advance.