Arcade nearly running for 365 days (8,4)
I believe the answer is:
calendar year
'365 days' is the definition.
The definition and answer can be both related to time as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'arcade nearly running' is the wordplay.
'running' indicates an anagram.
'arcade'+'nearly'='arcadenearly'
'arcadenearly' anagrammed gives 'CALENDAR YEAR'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for calendar year that I've seen before include "period of months?" , "January 1 to December 31 inclusive" , "Twelve months" .)