Ready to change a long time ago (4,3)
I believe the answer is:
year dot
'a long time ago' is the definition.
'ready to change' is the wordplay.
'change' indicates anagramming the letters.
'ready'+'to'='readyto'
'readyto' anagrammed gives 'YEAR DOT'.
(Other definitions for year dot that I've seen before include "Since this is as long as anyone can remember" , "As long ago as can be remembered" , "Earliest known period" , "Ready to (anag.)" , "A very long time ago" .)