with rws as (
  select person.name, 
  absence.start as dy, 
    case
          when absence.type = 'Vacation' then 'V'
          when absence.type = 'Homeoffice' then 'HO'
       end as text 

  from absence
    join person on person.id = absence.person)

  select * from rws
  
  pivot(
    min(text) for dy in ('06.03.2019', '06.04.2019')
    )

The pivot clause doesn't play nice with dynamic values sadly. There are various workarounds, which I discuss in the "Dynamic Column Lists" section of this blog post https://blogs.oracle.com/sql/how-to-convert-rows-to-columns-and-back-again-with-sql-aka-pivot-and-unpivot

If you can get away with numbering the columns, instead of the dates, you can:

- Use dense_rank() to number the dates
- Pivot the result of these numbers, up to however many days you want to show:

with dts as (
  select sysdate+level/5 dt
  from   dual
  connect by level <= 10
), rws as (
  select dense_rank () over (
           order by trunc ( dt )
         ) dr
  from   dts
)
  select * from rws
  pivot (
    count(*) for dr in ( 1, 2, 3, 4 )
  );

1    2    3    4   
   3    5    2    0

Or APEX has pivoting options built-in to interactive reports https://docs.oracle.com/en/database/oracle/application-express/19.1/aeeug/managing-pivot-reports.html#GUID-5B3D9691-91D8-43F0-B43E-293070473CA5

If you need help building the absence query for the pivot, please share:

- create table statements
- insert into statements of sample data
- the output you expect based on these