I do, and if you're eating very cleanly, no that shouldn't be too much of a difference...meaning only complex carbs, low GI foods, beef, casein, slow digesting foods. I wouldn't want to take it past 4 hours though. If you're getting 1200 cals in one sitting, of clean clean food, and doing this multiple times per day, then you're very disciplined and/or have a great appetite.
To get to 1200 clean calories in one sitting, would be pretty tough, for me anyhow. Whole milk, coconut milk (as a carb source), etc isn't considered clean to me, even though they easily boost cals (on paleo and modified diets). I don't eat grains either anymore now, which makes it even more difficult to get clean cals in.