Get Ready for Spring
Everything that is genuinely easier to install while the garden is asleep.
The argument is simple and almost nobody in this category makes it: a cable run through bare winter borders takes an afternoon. The same run through full May planting takes a weekend, and damages the planting on the way through. In January the ground is soft, the beds are empty, you can see the structure worth lighting, and a slit across the lawn has closed up by April.
Install now and the garden lights itself the moment the evenings are worth sitting out in. The full case is here, including what to do in which month and the two things winter installers get wrong.