What it means is if you have a one day auction, then the listing fee is 20 cents, if you have a 3 day auction, then the listing fee is 20 cents, if you have a 5 day auction, then the listing fee is 20 cents, if you have a 7 day auction, then the listing fee is 20 cents and finally if you have a 10 day auction the listing fee is 20 cents and you will be charged the extra for it being a 10 day auction. This means you only have today to launch these regular type auctions. They would close out respectively in one day, 3 days, 5 days, 7 days, and 10 days from now.
You would have essentially flooded the venues with your product for those time periods. But so will a lot of other folks. It is according to how many 20 cent extra auctions you want to give to ebay. They only do this to get extra revenue for themselves and you get to do a lot of work and maybe make a few extra bucks. For me its become more of nuisance in the scheme of things. However if your items normally sell and your listing fees are generally much higher then its a way of pushing against your competition for the available money to be made on those particular days.