the calendar directive is well usable without ikiwiki-calendar (eg for articles about meetings), but in such situations, it might be useful to have page creating links at the days.
from the new documentation (also in the patch):
newpageformat- In month mode, if no articles match the query, the value of
newpageformatwill be used to strformat the date in question. A good value is
newpageformat="meetings/%Y-%m-%d". It might be a good idea to have
[[!meta date="<TMPL_VAR name>"]]in the edittemplate of