Municipal laws that allow composting toilets usually require a two-year period of composting for any sort of animal waste, including composting toilet contents.
A skilled composter, using the right inoculants, huge quantities of poo, and operating in a warm climate, could probably get compost much more quickly than that.
But in a cool climate, and in quantities produced by just a few people, it takes some time before you get a product that is safe to put on your salad greens. And that's when compost is finished -- when it is safe to handle and use in a garden without burying it.