The Answer to which of these pictures was shot after dark, is the 'pine dining table' and the 'cream sofa with the two girls sat on it'. Lights were put in through the windows, then garden scenes, shot weeks earlier were added to the windows. If you click on the 'Photo Retouching' link above and have at a look at the 'night shoot' example, all is explained! The 'Client Portrait' link in the same section shows how a dark rainy day can also be turned into a sunny summers day! If only I could do the same in the real world!
If this technique would help with the problems you have with short shoot days in the winter months, please do call; I'd be happy to come in and discuss your requirements! I'll even buy you a pint if you got the answer right! ;-)