Well, you confused me for a while too.
Most people would count the age of a queen from the date of emergence, because, she's not an adult until then.
A queen becomes sexually mature around 6 days post emergence and this generates a lot of excitement among the workers as they anticipate her mating flight(s). However, II is dependent upon coordinating the availability of both semen from preferred drones and maturity of the virgin queen. It is probably better to inseminate 8-10 days after emergence so you can be sure the queen is mature. Of course, this means the queen must be prevented from flying with an excluder over the entrance.
My apologies to the OP. This thread seems to have drifted somewhat.