Unique system that seems nothing new on some days (3,3)
I believe the answer is:
one way
'unique system that' is the definition.
I can't tell whether this definition defines the answer.
'nothing new on some days' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'on' is a charade indicator (letters next to each other).
'some' means to look at the middle letters.
The middle of 'days' is 'ay'.
'o'+'new'+'ay'='ONE-WAY'
'seems' acts as a link.
Can you help me to learn more?
(Other definitions for one way that I've seen before include "getting no comeback?" , "Perhaps unrequited" , "permitting no U-turn" , "Description of certain roads" .)