Arrive
ready.
Jet lag costs peak performers days of diminished output. Time Transit builds a personalized adjustment protocol from your exact itinerary — rooted in circadian neuroscience, delivered as a precise daily timeline.
01 — THE COST
after a transatlantic eastward flight
Your circadian clock — a 24-hour biological timekeeper anchored in the suprachiasmatic nucleus — doesn't passively reset when you land. It shifts at approximately one hour per day, meaning a six-hour eastward journey leaves you biologically misaligned for nearly a week.
The consequences are measurable: sustained impairments to reaction time, working memory, emotional regulation, and metabolic function. For frequent flyers, this isn't occasional inconvenience — it accumulates into chronic circadian disruption with long-term health consequences.
Modern circadian science has mapped the solution. The clock responds to precise environmental inputs — light, darkness, meal timing, temperature, and melatonin — in predictable, mathematically modeled ways. Time Transit applies this model to your specific journey.
The
Protocol.
Three steps from itinerary to a precision circadian adjustment schedule. No circadian biology expertise required.
Analyze Your Route
Enter your departure city, destination, and travel dates. Time Transit calculates your current circadian phase using DLMO estimation, models the phase shift required, and identifies your optimal adjustment strategy — advance or delay protocol.
Receive Your Protocol
Your personalized plan specifies precise light exposure windows, darkness periods, melatonin timing, caffeine cutoffs, and meal schedules — beginning days before departure and continuing through arrival. Every recommendation has a reason rooted in your phase curve.
Follow in Real Time
Push notifications arrive at exactly the right moment — seek light now, begin darkness, take melatonin. The app's timeline view shows your current phase position, next transition, and protocol progress at a glance. No thinking required mid-journey.
03 — THE SCIENCE
Built on
peer-reviewed research.
ZEITGEBERS
Light is the primary clock signal
The suprachiasmatic nucleus resets via retinal light input through intrinsically photosensitive retinal ganglion cells (ipRGCs). Short-wavelength light (480nm) has maximum phase-shifting potency. Time Transit's light windows target the ascending and descending limbs of the phase response curve for maximum efficiency.
PHASE MODELING
Your DLMO predicts your optimal timing
Dim Light Melatonin Onset — the point where melatonin secretion begins in dim conditions — is the gold standard marker of circadian phase. Time Transit estimates your DLMO from chronotype and travel history, then uses published Phase Response Curves to calculate precisely when light and melatonin will shift your clock most effectively.
SECONDARY ZEITGEBERS
Meals, caffeine, and motion amplify the shift
Peripheral clocks in the liver, gut, and skeletal muscle entrain primarily to feeding cycles. Strategic meal timing reinforces the phase shift initiated by light. Caffeine's adenosine antagonism is timed to support alertness during the adjustment window without blunting the natural melatonin rise that consolidates the new phase.
TIME TRANSIT FOR iOS
Your optimal
rhythm. Anywhere.
Available for iPhone. iOS 16 or later required.
Integrates with Apple Health for sleep and activity data.