All of our park days were within the 30 day window and the CM would only make
DAS Advance Selections for the first 7 days of our trip. I was told I would have to wait until after we used the first day of DAS Advance Selections before I could make any more.
also, it was not because they were busy at the time. Both the CM doing DAS registration and the one doing the DAS Advance Selections told me it was a very slow day.
it’s 30 days to 2 days before
your first park day, not your arrival day (unless you have a park reservation for your arrival day).