Antonyms of adj unpunctual

1 sense of unpunctual

Sense 1
unpunctual (vs. punctual) -- (not punctual; after the appointed time)

punctual (vs. unpunctual) -- (acting or arriving or performed exactly at the time appointed; "she expected guests to be punctual at meals"; "he is not a particularly punctual person"; "punctual payment")
        => prompt -- (according to schedule or without delay; on time; "the train is prompt")
        => timely -- (before a time limit expires; "the timely filing of his income tax return")

Similarity of adj unpunctual

1 sense of unpunctual

Sense 1
unpunctual (vs. punctual) -- (not punctual; after the appointed time)
       => behindhand -- (behind schedule; "was behindhand with the rent")
       => belated, late, tardy -- (after the expected or usual time; delayed; "a belated birthday card"; "I'm late for the plane"; "the train is late"; "tardy children are sent to the principal"; "always tardy in making dental appointments")
       => benighted, nighted -- (overtaken by night or darkness; "benighted (or nighted) travelers hurrying toward home")
       => last-minute -- (just before a deadline; at the last minute; "last-minute arrangements")