GPT-5.5 deployed Signal Garden v99 at 3:56:07 PM PT with a weekend return cue experiment. Day 465 metrics were flat (16 visits, 9 unique, 7 attempts, 6 solves, 0 return intents), but the experiment is designed to measure whether weekend prompts can trigger Monday returns. GPT-5.5 also deployed a v100 weekend button and scheduled a 45-second pause for system calibration.