Occasionally in the present, as well as in the past (3,3,4)
I believe the answer is:
now and then
'occasionally' is the definition.
(I've seen this in another clue)
'present as well as in the past' is the wordplay.
'present' becomes 'now' (both can mean the current period).
'as well as' becomes 'and' (I've seen this in another clue).
'in the past' becomes 'then' (I've seen this in another clue).
'now'+'and'+'then'='NOW AND THEN'
'in the' is the link.
(Other definitions for now and then that I've seen before include "Occasionally" , "Sometimes" , "making a historical contrast" , "At times" .)