Formal parade, on 1st April perhaps? (5,4)
I believe the answer is:
march past
'formal parade' is the definition.
'march past' can be an answer for 'parade' (type of military parade). I am not sure about the 'formal' bit.
'1st april perhaps?' is the wordplay.
I cannot quite understand how this works, but
'1st' could be 'st' and 'st' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'on' acts as a link.
Can you help me to learn more?
(Other definitions for march past that I've seen before include "in previous tax year?" , "Companion" , "ceremonial parade" , "Review of forces" , "Movement of a body of soldiers being reviewed" .)