Unless the purchase agreement states a revised possession date, it likely has the seller giving possession on the day of funding. In this case, it sounds like your day of funding was set the day after closing (which is common).
If you need more time, you'll want to have your realtor act quickly to either draft an extension or negotiate an occupancy agreement.
Syan Real Estate
Call/Text: (505) 730-8181
Check your sales agreement. That'll give you the answer.
However, in general if you're selling, you really are supposed to be out of there by closing. After all, you no longer own the property. (There's a bit of wiggle room, since legally ownership doesn't transfer until the deed is officially transferred, which may occur the same day of closing or perhaps the next day.)
Hope that helps.