Tagging an item with the specific date will pre-schedule a post or tweet to FB/Twitter, provided both FB/Twitter are connected to your account. You can connect both your FB and Twitter account, or you can connect either your FB or Twitter account.
To do this: Go to Account settings> social networks and enter the credentials for the accounts you want to post from.
Note to connect FB you must also go to account settings>social merchandising and check Enable FB
How to feature an item:
On Wishpot go to your List page
To the right of the item you want to feature click 'edit'