German phrase
Wann würde es Ihnen passen?
Meaning
When would be convenient for you?
When to use it
It asks when you are free. The polite wording gently supports arranging a time.
Example dialogue
Wann würde es Ihnen passen?
When would be convenient for you?
Am Freitagnachmittag würde es mir passen.
Friday afternoon would be convenient for me.