Scores of time left - that is special! (8)
I believe the answer is:
twenties
'scores' is the definition.
(I've seen this before)
'time left that is special' is the wordplay.
'time' becomes 't'.
'left' becomes 'went' (I've seen this before**).
'that is' becomes 'ie' ('i.e.' can be a synonym of 'that is').
'special' becomes 's' (common abbreviation as in Special Air Service).
't'+'went'+'ie'+'s'='TWENTIES'
'of' is the link.
(Other definitions for twenties that I've seen before include "decade of frivolity" , "The decade was said to be roaring" , "They were roaring in the last century" , "what lies ahead for 27 [TEENAGER]?" , "period of years" .)