User blog comment:IamJakuhoRaikoben/Chapter 468: Memory of the Stars, Review./@comment-7418318-20160109195533/@comment-25111584-20160109200023

It could be that the person on either side opens to Gate to a specific time? Anna could have opened it to 7/7/X777 and had the info passed down, so that somebody present in that period could open the Gate to her time at precisely that moment? I actually thought this is how it works...