Pass Activation exactly 30 days before use for 7 day regional pass

Hi JR PASS,
I ordered a regional 7 day JR Pass on Sun Aug 10 through your website in preparations for my trip to Japan. I understand that Japan only allows reservations for online JR passes exactly one month before boarding, starting at 10:00 am JST. Note: Aug 10 is several days ahead of month out of the dates I need the pass on Sept 18, 2025.

I will in Osaka on Sept 10, 2025. I am going to Kyoto on Sept 18,2025. I ordered a 7 day regional pass from you & for only Sept18 to Sept 25,2025 because those are the dates I need the JRPASS. I also purchased the Meet & Greet for my arrival at the airport where my voucher will be activated on Sept 10.
My Question:

If I activate the pass at the airport on Sept 10 can that pass be used for Sept 18? Or do I need to re-book a JRPASS on Aug. 18?