I am not suggesting you are stretching the truth, but what sort of jobs are they you have booked in? As in my experience nobody is ever prepared to wait more than a couple of weeks or so for the majority of work.
like I say, I don't doubt you but find it hard to believe that you have electrical work booked in that far in advance.
If I advertised then my customers would have to wait that long.
Any sensible person factors in existing customers projected demands in to their workload.
Any gaps you leave in your diary will soon be filled.
Most if not all of my customers are happy to wait or are at least organised enough to plan well ahead for installation work.