Time for March madness? (4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
ides
(Other definitions for ides that I've seen before include "Fatal March date or Julius Caesar" , "Julius Caesar's unlucky day in March" , "One da" , "Mid-month date in Roman calendar" , "'''Beware the ... of March'' (Julius Caesar) (4)'" .)