When my mother was still living she used to bake a very rich fruit cake. It was the sort of thing that she'd start preparing literally months in advance, soaking dried fruit in brandy and turning it every once in a while. Then, once the cake was baked, it was best left to sit for a time - sometimes many weeks or months. What made it even richer was that sometimes she'd pour an ounce of brandy onto the top of it to soak in, and repeat every month for a few months.
She made the same kind of cake for Christmas, and I think she'd typically start preparing it 18 months ahead of time. That gave her a few months to soak the fruit in the brandy and then run the oven to cook the cake during the winter months and have most of a year for the cake to age and mature. It didn't need a full year but the oven ran hot enough for long enough she understandably didn't want to make them in the summer.
