Days gone by certainly sad without a listener (10)
I believe the answer is:
yesteryear
'days gone by' is the definition.
(I've seen this before)
'certainly sad without a listener' is the wordplay.
'certainly' becomes 'yes' (both can be used to answer in the affirmative).
'sad' becomes 'teary' (likely to burst into tears).
'without' suggests deleting specific letters.
'listener' becomes 'ear' (body part which hears or listens).
'teary' with 'a' removed is 'tery'.
'yes'+'tery'+'ear'='YESTERYEAR'
(Other definitions for yesteryear that I've seen before include "The recent past" , "Former times" , "Time disappeared" , "Twelve months ago" , "Rossetti's translation questioned whereabouts of its snows!" .)