I do think a little later is good BUT I don't like Jan/Feb seed swaps. I never get seeds in time to plant them. Almost all the seeds I got from last year's swap are still waiting to be planted. I have a short season so I start a lot of seeds in January. So that is my busy period. October or early November would be my choice.
I think 7 days is a bit long for a swap. I'm out of steam by the fifth day and rarely bid on anything after that. But if you cut down the time then you'd have to up the number of bids we get to start with or some people won't get all the seeds they want.
Personally I'd love to try a one day swap but I think we'd all have to agree on a day that most people would have the free time. I'm also not sure how that would work with using and gaining more bids. Does the system allow you to change the time it takes to accrue new bids?
DND you posted while I was typing. I learned it's better to clean & package seed as soon after harvesting as possible. If you leave it until you are less busy it becomes a daunting task.