Sprwt computes two dates for every auto-renewing subscription:

1. Renewal date = last renewal date + Weeks, moved to the plan's Billing Renew Day weekday.
2. Charge window start = renewal date − Buffer Days to Charge Before Renewal.

The renewal job (run automatically by Sprwt) charges the saved card for any subscription whose window has started, and for subscriptions whose renewal date has already passed as long as the previous attempt did not error. A successful renewal creates a new paid order for the next cycle starting at the first upcoming delivery date that matches the subscription's delivery days and the kitchen's online days, then sends the "subscription renewed" notification. If the charge fails, the subscription is flagged on error, the customer receives the renewal-error trigger and the store receives the admin error e-mail. Manual-renewal subscriptions (auto-renew off) are never charged automatically.