Prepare yourself for possible disappointment and have a good read through the many, many topics on this forum about delayed cable installations.
It is sensible to oversee what VM, or its contractors, get up to with the cable laying and make sure it is done to your satisfaction, if you can, and the cable goes where you want it to but, generally, VM don't necessarily expect customers to be in for the external work of laying the cable.
VM don't seem to directly control the activities and schedules of the sub-contractors who lay cables for them. As a result, you should regard any dates VM give you as estimates of when they might turn up and nothing more.