Bedding Time for new Valves and guides on a 10 year old CB unicorn done at a local mech shop?

Is there anything like bedding time when Valves are changed and guides are changed with new seals for a 10 year old Cb unicorn 150 ? if yes, what happens during the Bedding time and how long does it take to settle down(in kms)? Does the valves leak oil/oil moisture during the bedding time?