Day in Rome that is timeless (4)
I believe the answer is:
'day in rome' is the definition.
(Roman calendar term, as in the Ides of March)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for ides that I've seen before include "March day Caesar died" , "Day in Roman months" , "March day fatal to Julius Caesar" , "Caesar was killed in this side of March" , "Julius Caesar was killed during the . . . . of March" .)