Move your body clock, one hour at a time.
Tell Phaseshift when you usually fall asleep and wake up. We back-extrapolate your DLMO — the moment your brain starts releasing melatonin — and turn it into a day-by-day plan: when to take melatonin, when to seek bright light, and when to keep the lights low.
Adjusting to a different time zone?
Flip this on to see every event in both your home and destination zones — handy for jet-lag prep or shift-work travel.
Your current rhythm
Healthy adult window (7–9h).
Your target rhythm
Healthy adult window (7–9h).
Phase assessment
From the times you provided, we estimate the two anchor markers of your endogenous circadian phase. DLMO (Dim Light Melatonin Onset) marks the start of the biological night and is the validated phase marker used in research; CBTmin (core body temperature minimum) defines the inflection of the human Phase Response Curve (PRC) — light before CBTmin delays the clock, light after CBTmin advances it.
Back-extrapolated as habitual sleep onset − 2 h (Burgess & Eastman, 2005). In normally entrained adults DLMO precedes sleep onset by ~2 h; sleep typically follows ~2–3 h after melatonin onset under dim light (<5 lux).
Estimated as habitual wake − 2 h. CBTmin is the PRC inflection point: ≤6 h before CBTmin yields phase delays; ≤6 h after CBTmin yields phase advances of ~1–3 h to a single bright-light pulse.
The DLMO you are entraining toward. Sustained shifts of the DLMO of ~1 h/day are achievable with combined timed light + low-dose melatonin; without intervention, the human clock free-runs ~24.2 h, biasing spontaneous drift toward delay.
Use this to time morning bright light (post-CBTmin = advance) or evening bright light (pre-CBTmin = delay). Mistiming light by even 2–3 h relative to CBTmin can produce the opposite of the intended shift.
3-day, ~30–60 min/day advance
Pulling the clock earlier is the hard direction. Melatonin acts as a 'dawn signal' in the late afternoon; bright morning light locks it in.