It wouldn't take a week. Within a few days he'll probably cover all of them. They should produce fertile eggs for at least a week, probably 2weeks, possibly 3 weeks. Since you are best off setting eggs within 1 week of collecting it's not really an issue unless you want to sell fertile eggs or set multiple hatches. Otherwise you'd only need to mate your hens out for a few days every month to keep your incubator running constantly.