1/2 Day attendance for Elementary School

Our policy for our elementary states this: Early dismissals occurring before 11:30 am will be counted as a full-day absence. Those occurring between 11:30 am and 2:30 pm will be counted as a half-day absence.

My Question is how do we handle 1/2 day absences? I have only been in schools that use per period attendance but now I have a school that uses full day/half day and I am just not sure how to set that up.