I have deleted the database to add the read start with 0% afterwards.
With chaley's help and search & replace it also worked easily.
Now the problem comes.
All the new date entries in Calibre have a 00:00:00 CEST. I now have a timeshift of -1 day.
Edit:
A book about the turn of the year will not be moved to the next year. It remains ‘Want to read’ 2017.. Once again ignoring the difference between annual overview and all
Edit2: What am I doing wrong, no reread counter?
Edit3: I saw another thread and it looks like the timeshif is a DST thing. Does somebody know to change the 00:00:00?