French phrase
Quand cela s'est-il produit ?
Meaning
When did it occur?
When to use it
Asks for the time of a past event. The wording is formal and suits meetings, reports, and written communication.
Example dialogue
Quand cela s'est-il produit ?
When did it occur?
C'était mardi matin, juste après la livraison.
It was Tuesday morning, just after the delivery.