Halfway to tomorrow (4)
I believe the answer is:
noon
'halfway to tomorrow' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for noon that I've seen before include "Twelve during daylight" , "High time of day?" , "See 8" , "when only mad dogs go out?" , "Twelve o'clock in the day" .)