One day short of calorie goal?

Yesterday I was just TOO busy to eat anything.  Come the end of the day, my CC said that I'd only consumed 900 Cal.  I normally hit (and exceed ) my target of 1377.  My question is: On the odd day that I am significantly lower, should I find extra food to eat in order to get above the important 1200 Cal lower limit, or should I just leave it for the day and assume it will all even out in the end?

I don't think it'll hurt you... as long as you aren't not eating enough every day it shouldn't be a problem.  If you think you should eat a little more at the end of the day, maybe just chop up an apple or have a piece of toast.  Trying to over compensate for under eating at the end of the day is probably a bad idea as whatever you eat at night will digest extemely slowly and may interfere with sleep.

One day isn't going to hurt you.  Several days will.  If you need to get in some quick cals at the end of the day, eat some peanut butter or something else that is calorie dense that way you get some needed cals without a lot of bulk.