Eating my Calorie Count advice

Eating my calorie count.

Okay so how important is it that I eat my calorie count. I know that if I eat too little my body will go into starvation mode but I did eat almost up to my alloted 1200 calories. The thing is I worked out today as well and I burned a bunch of calories. Of course that means I should be able to eat more. However, my day is almost over and I'm not actually that hungry so my question is this.

Should I go home and try and find a healthy snack to eat so I'm closer to my calorie goal or is it okay to be 3-400 under one day as long as I didn't starve myself. I think my diary is open to everyone so you can feel free to look if you like.