Obscure period without Sun and Times? (4,4)
I believe the answer is:
dark ages
'obscure period' is the definition.
'without sun and times?' is the wordplay.
'without sun' becomes 'dark'.
'and' says to put letters next to each other.
'times?' becomes 'ages' (age is a kind of time).
'dark'+'ages'='DARK AGES'
(Other definitions for dark ages that I've seen before include "Late 5th century to around AD 1000?" , ""unenlightened" Times" , "Period of supposed unenlightenment" , "'Period of history between classical antiquity and the Italian Renaissance (4,4)'" , "Period after the fall of Rome" .)