Would it be possible to count the number of empty cells in a column,
that fall between the first occupied cell and the last occupied cell
in a range.

For example if A5:A20 can be populated, but the first occupied cell is
A8 and the last occupied cell is A12, I wish to count only those cells
that are <blank between A8:A12

Another example would be if the first occupied cell was A13 and the
last occupied cell is A15, I wish to count only those cells that are
<blank between A13:A15

If you could visualise the above being Clock in / Out times, I wish to
know what part of the day there is no job allocated

Thanks