I had the same problem over the summer. I struggled to get enough calories, and I didn't know how to fix it. Best thing I ever did was buy a tub of CytoGainer. One 4 scoop (1 serving) shake a night and I was finally able to hit my calorie target (and I was able to pack on the muscle).I'm surprised this thread is still going on.
Last night I consumed about 700 calories to meet my daily requirement. Between 10:30 and 11:00 I had homemade hot chocolate, yogurt, a banana and some oil.
Sometimes I just CANNOT get enough calories during the day. I have to extend the eating inot the night. There is no way I could EVER get enough calories before 8:00 PM. I have to eat lots of tiny meals throughout the day and into the night.
I would highly recommend a weight gainer (CytoGainer tastes AMAZING) if you are having trouble hitting your calorie needs.