promptness vs promptitude

promptness and promptitude both are nouns.

Word	Noun	Adjective	Verb	Adverb
promptness	Yes	No	No	No
promptitude	Yes	No	No	No

As nouns, promptness and promptitude are synonyms defined as:

promptness and promptitude: the characteristic of doing things without delay

promptness (noun)	promptitude (noun)
the characteristic of doing things without delay	the characteristic of doing things without delay
the quality or habit of adhering to an appointed time