is thursday the absolute last day to buy an iphone 13 from the apple store?

I had the same question 2 years ago, where I wanted to buy a 12 mini but they took it off online already but they still had them in-store. the iphone 13 is now removed from the lineup, but they still have them in-store but inconveniently I forgot to ask when would be the absolute last day to buy it. they say the 16s come out on the 20th which is this friday, so I’m thinking thursday would be the last day to buy it? thoughts?