All right have read every post in the "How to Upgrade" thread since eupgrades were introduced and still have some questions?

Please confirm I can request an upgrade based on the applicable status, days or hours prior to departure? Prestige = 2 days/48 hrs so Flight July 3 YVR-HkG dep 1230pm means I can request an upgrade anytime on July 1 (12:05am hypothetically) or can I only request at July 1 1230pm?

If the above itinerary starts in YYC at 10am July 3 does that mean I have to wait until 1230pm July 1 to request my upgrade?

Last question what happens if I booked the above flights via lufthansa but all flights are AC operated?

Thank you and likely this has been posted elsewhere but I could not find the information.