Update tier progress after the last customer activity - The formula is: (Current date - Threshold days) if any activity is found: (Activity days + Threshold days). This would set up customer’s tiers depending on when they last did something. For example, if a customer's last activity was 5 days ago and you set the threshold to 10 days, the system will check their activity 10 days ago from now. Since the customer's last activity was 5 days ago, their VIP status will be reviewed again 10 days after that activity.