Once a Listing is created, it may not appear live on the Marketplace until it's been approved. Each new Listing goes through an approval process for validity purposes and to prevent fraud.
You may keep your listing for sale on the Marketplace as long as you still own the PSLs. You can cancel listings from your account dashboard under Selling and Current Listings.
Each new listing is set to automatically expire after 180 days but sellers may renew the listing at any time for an additional 180 days.