I add lights every year. I already know what I'm doing next year.
The department stores start putting out Christmas items around the third week in October, though they're not really fully stocked until about the second week of November.
That means, for those three weeks, I'm in there every two or three days, checking for whatever lights I need, because if you wait...those lights will get stocked and sold out in about three days' time, then you're stuck waiting for the next shipment. That's especially problematic this year (and last).
I tried to buy Christmas lights today, and they were sold out.
That's my story, and I'm sticking to it.
CD