The builders are coming

This is what I came home to yesterday morning after night shift. The building materials for the car parking spaces and the front path has arrived. Only one set of stones was wrong - the wrong type was delivered. This should be rectified in the next couple of days.
So the material is here, but we do not yet know when the builders will be. In theory it should be next week, but experience has taught us that it will probably be the week after, or the week after that, or the...........