Randy thanks. There are some diaries but they are open for everybody or open for everybody if logged-in. Not for a certain user.
I agree that I have to start a little project to rewrite a plugin.
It would not be a great project:
a logged in user can sequential add text per date/time
only the user with the right userid can do this
in his own admin environment he can look into his diary top-down
add a new records + automatically date/time registration.
thats it.
Just tested this, but with no results.
All check-boxes are unselected in the page section: Show on screen
Revisions Custom Fields Discussion Comments Slug Author Page Attributes Featured Image
Also refreshed cache.
Oeps. You have to choose Quick Edit not Edit then unselect Allow Comments. After saving it works!