Due to ring the day after (4)
I believe the answer is:
owed
'due' is the definition.
(synonyms)
'ring the day after' is the wordplay.
'ring' becomes 'O' (letter resembling a ring).
'the day' becomes 'wed' (abbreviation for Wednesday).
'after' is a charade indicator (letters next to each other).
'o'+'wed'='OWED'
'to' acts as a link.
(Other definitions for owed that I've seen before include "Was indebted" , "In debt to" , "Was obliged to pay" , "(Sum) due for payment" , "Was due to pay" .)