Even though temps might be in the 70's some northern folks do not like to dig and divide their plants after a particular date, some use Labor Day as the cut off. Also possible the seller is listing a df (2 blooming size fans) and by spring the second fan will be "blooming size".
I've never worried about bidding on the LA for spring shipment even though it may be 7 or 8 months away. Years ago I would have 50 to 150 plants coming in the spring...oh those were the days...and I would bid for any daylilies I really wanted to add to the garden. Now there are maybe 10 -20 that come in the spring. I do keep a written list of the plants I've won and the seller. Also keep a sticky note of the plants won near the computer so I don't goof and forget I already won that one! There is also a sticky want list.
I don't do Ebay.
