You can delete "bad" trips.
If you ever touch the brakes or don't turn like a grandma:
Reset To Delete a Bad Trip or Event
You can also delete a trip with a Forward Collision Warning or Autopilot Disengagement.
And it is not a certain number of days.
It is when a current release is good enough to have let all existing beta testers in first.
TeslaFi seems to be showing that Tesla is only letting the 4,000 10.6 users get 10.6.1.
Then Tesla will upgrade the other existing beta testers (now 16,000) before they will bring in new users.
You can watch it unfold on
TeslaFi.