The documentation for org-agenda-custom-commands
<https://orgmode.org/worg/org-tutorials/org-custom-agenda-commands.html> at
https://orgmode.org/worg/org-tutorials/org-custom-agenda-commands.html uses


org-agenda-ndays

in the customization instead of

org-agenda-span

org-agenda-ndays  is deprecated in org-version 9.


Can somebody update it because it took me an embarrassingly long time to
figure out what was wrong with my customization.