At the same high school for 9th, 10th and 12th, but went to a different school for 11th grade.
Would the Date of Entry on the Common App be this year July, 2016 to match the re-enrollment in current school or is it July 2012 when first entered as a freshman?
I think there is a tab to put the different high schools you went to, you just have to click ‘add school’. So I think you would put the date that you first entered high school in, I don’t think they care about what years you went to each one, just the one you entered as a freshman and the one you graduated from. (hopefully I’m right about this, but I’m not 100% positive)
You can call admissions offices at the schools you are applying to to make sure you are doing the right thing, or ask your college counselor, but I think you would list your first school, second school, and then your first school again, since you re-entered.