Order: "Please pick up your item by Sep 23" - till the end of the day?

Hello,

I have ordered a new iPhone with pickup date on 16th September at 9 AM. I will be able to pick up it on 23th September.

Order page shows:

"Please pick up your item by Sep 23"

Does it mean that my order will wait till the end of the day 23 Sep or till 9 AM 23 Sep?