Currently the text reading out a shipping methods ETA cannot be modified. It will always say Estimated arrival in X business days.
This can be misleading for some people when you have to consider things like handling time. in some cases you may want it to say
Estimated arrival in X business days from date of dispatch.
Other times your ETA may not be measured in business days, perhaps you use a carrier that can ship on weekends
Estimated arrival in X days
