Inserting rows
 

I have a column which shows the time in half-hour intervals, eg 12:00, 12:30 and so forth. However sometimes, not all intervals are present eg 12:00, 01:00.

Is there a macro which can find this missing intervals and inset row/s for them? Each day starts with 12:00 (am) and end with 11:30 (pm).

Any help is greatly appreciated.
Aloys