French phrase
Quel est le délai de validité de ~ ?
Meaning
How long is ___ valid?
When to use it
Used to ask when a validity period ends. Neutral and common for tickets, medicines, and similar items.
Example dialogue
Quel est le délai de validité de ce billet ?
How long is this ticket valid?
Il est valable jusqu'au 15 août.
It's valid until August 15.