Classes getting info on time (6)
I believe the answer is:
genera
'classes' is the definition.
(I've seen this before)
'info on time' is the wordplay.
'info' becomes 'gen' (gen is a kind of info).
'on' means one lot of letters go next to another.
'time' becomes 'era' (I've seen this before).
'gen'+'era'='GENERA'
'getting' is the link.
(Other definitions for genera that I've seen before include "Categories making up a family" , "similar groups" , "Biological groups" , "Types" , "Groups with common characteristics" .)