dyscalendia

Analogous to dyslexia (bad with words) or dyscalculia (bad at math).

Etym; dys (bad) + calends (Roman 1st day of month, when rent and bills are usually due) + -ia (state or disorder).

Means one has trouble keeping appointments.

With my dyscalendia, I'm often too early or late for salon or doctor visits.