Source : Webster's Revised Unabridged Dictionary (1913)

Patness \Pat"ness\, n.
   Fitness or appropriateness; striking suitableness;
   convenience.

         The description with equal patness may suit both.
                                                  --Barrow.

Source : WordNet®

patness
     n : timely convenience [syn: {opportuneness}, {timeliness}]
         [ant: {inopportuneness}]