From whenever the date provided about when the Box first stood means almost nothing as the real work is about getting power to the damn things. Other factors like traffic management for any digging work may only be allowed on weekends by certain councils this compounds the waiting time. There are also other issues which have to be worked out before the cabinet actually goes live.
I knew your frustration prior to my cabinet gong FTTC live..
It seemed at the time that the whole world was conspiring against me and its true, well, at least in my case everyone in my neighbourhood could get FTTC but who were already on a decent service could get FTTC except me..
Luckily, my patients prevailed and my cabinet went live before the actual BT checker Availability Date plus my connection speed is double what the BT checker estimate stated.
I hope it all turns out well for you, just hold tight and keep your fingers crossed !