Originally Posted by
bmwe92fan
or possibly a mis-translation as I've entered trip details more than 7days before departure and the gates fly open without issue....
I think you are onto something there. This motivated me to go look at the original Japanese text where they write, "...遅くとも12時間後には利用することができます"
遅くとも is "at the latest", 12時間後 can be "12 hours later", the rest is "you can use".
So probably the correct translation is, "at the latest it may take us 12 hours to process, after which you can use it.", or "at the latest it may be 12 hours, after which you can use it."