If I have been getting up at 9:23am on average, what is the earliest I can get up to phase advance my circadian rhythm the fastest without causing phase delay

With a 9:23 a.m. average wake time, the transcripts don’t establish an exact “earliest safe” wake time. A practical approach is to move earlier in small steps and pair the new wake time with light at the right circadian phase: light in the four hours after your temperature minimum tends to advance the clock, while light in the four to six hours before it can delay the clock. Your temperature minimum can be estimated from your average wake time over several days, but the material here does not give a specific minute-by-minute wake-time schedule for your situation. 1

• Bright light after waking: Get bright light—ideally outdoor sunlight—as soon as practical after waking; morning light supports phase advances. 2
• Avoid phase-delaying light: Keep evening light low, especially bright light late at night and in the middle of the night, which can delay the clock. 3