Relay arranged, in good time (5)
I believe the answer is:
early
'in good time' is the definition.
(being early is arriving in good time)
'relay arranged' is the wordplay.
'arranged' indicates an anagram.
'relay' anagrammed gives 'EARLY'.
(Other definitions for early that I've seen before include "Prematurely" , "Before the usual time" , "before anyone else?" , "in the morning?" , "Immature" .)