When to take possession upon closing on a house

Is there any financial ramification for a buyer if he closes on a house at the end of the month, but the sellers aren't able to move out until two weeks later?

The biggest one I can see is that the buyer will be paying the mortgage while someone else lives in the house!

That is unfair, unless you can get the seller to pony up the difference and its not a major inconvenience for you to wait the extra couple of weeks. Legally the sellers should be out unless you have a private arrangement with them.

If the sellers aren't able to move out until a certain date then they should be upfront and ask if that's alright, or ask to have the closing date moved back 2 weeks. There are really no financial ramifications, other then yes paying a mortgage on a house someone else is living in, however it's also courteous to allow them that time to move should they so need it, unless you need to be on the property immediatly for reasons of your own.

Biggest risk is if the seller's do anything in the mean time to de-value the property...removing appliances, damage, etc. As the owner, you would also be liable if they were injured in 'your' house. This arrangement occurs many time in real estate transactions & many times is the only way the selling party can have the money they need to complete a closing on the new home they might be buying. Just make sure the arrangment & stipulations are in writing if you decide to go this route. I allowed my seller to continue to use the garage for storage of their belongings for 2 months while their new home was being built, in exchange I had a source of ongoing information about things in my new house, and required that they provide me with a product that they sell. (Very large stuffed bears for outdoor displays!)