To try and steelman it: With Tesla you buy the car online, and don't sign the papers until you pick up the car. The day you sign the papers is perhaps the d

To try and steelman it: With Tesla you buy the car online, and don't sign the papers until you pick up the car. The day you sign the papers is perhaps the day you're considered to have bought the car, rather than the day you press the "buy" button. The cars tend to arrive in large batches, so it's very possible that a single months worth of sales arrived all on the same day and those papers were all signed on the same day.