You can apply compost anytime. Mulches (and a compost top dressing would be a sort of mulch) have some considerations.

Certainly they can be left on year round, but for overwintering plants that were not mulched previously it's common to let the earth freeze before adding it. This is to insulate the earth against the cold to come as well as to prevent the earth from thawing on the sunny/warm days in winter. It just helps keep soil temps more consistent.

If you add compost when the soil is cold it won't do much in terms of being broken down by soil life as they sleep when the soil is cold, but they will appreciate the meal come spring time.

This compost, is it just from leaves that you have piled into a bin or has it gone the entire route, with added materials to make a more complete organic compost?

If its just leaf mold, leaves that have been put into a bin or maybe bagged and left to break down, then holding it until next summer makes sense. AT that time it would make a great mulch and mix for roses and other perennials.
The more complete a compost becomes is better for what its designed for, to feed plants.

Myself, I prefer to have a clean garden over winter. In spring the compost can be placed where it'll do the most good.

Compost can be put on soil anytime and fall is as good a time as any to do that. Soil should never be left bare and exposed to the ravages of the the weather because that erodes your good soil. Since it can take several months for the Soil Food Web to work compost in to your soil putting it own in the fall is better than spring because then the nutrients in that compost will be where they need to be when they need to be there. Waiting until spring to apply compost can mean those nutrients won't be down in the root zone until after your plants have grown.

FAll is usually when I put compost down. I empty out the finished compost in the fall, so I have room for the fall leaves.

I like to get the compost down first and then I cover the compost layer with shredded fall leaves and after they have set over winter, the soil is great for planting next spring.

Conpost makes an excellent mulch and it can be applied any time. In zone 7, there is little concern about soil freezing or plant heaving, so applying for winter protection (waiting to apply after the soil freezes) is moot. As kimmsr states, it is far better to have the soil covered in winter to reduce erosion and compaction from rain water than to leave it uncovered and fall, after plant foliage dies back and the soil is more exposed, is an excellent time to do so. But any mulch will work similarly.

Compost is primarily considered a soil amendment, not a fertilizer. While it does provide an excellent source of organic nutrients, their concentrations are quite low and variable depending on initial ingredients. What it does provide consistently is improvement to soil structure and therefore tilth and drainage, replenishment of organic matter and a hospitable environment for soil organisms.

Under leaves, on top of leaves (to hold them in place), instead of leaves, I use it everywhere this time of year. Or any time of year the compost isn't frozen, for that matter.

tj

jeannie7, it is compost that I made with leaves, grass clippings and small amount of garden plant waste. I just took it out of my compost bin so I can start putting this year's leaves and other fall clean up stuff in.

I guess the consensus seems to be that I can just apply it now. Thanks for all the great comments!