What is the Jet Lag Planner?
Estimate how many days a gradual sleep adjustment might take after crossing time zones.
This Calcwise tool is built around the question a user is actually trying to answer. The main result explains the outcome in plain language, while the supporting figures show how the answer was produced.
How to use this calculator
- Replace every example value with your own numbers.
- Read the What this means guide directly under each input.
- Check the main answer and the supporting breakdown.
- Enable Pro mode to compare an alternate shiftPerDay scenario without losing your main inputs.
Inputs used
- Home UTC offset — UTC offset where your normal sleep schedule is set. Example: 5.5
- Destination UTC offset — UTC offset at the destination. Example: -4
- Travel direction — Eastward shifts are often harder for many people than westward shifts. Example: west
- Planned sleep shift per day — How many hours you plan to move your sleep schedule each day. Example: 1
Jet Lag Planner formula
The formula is shown so the result is not a black box. Where the result is an estimate, the assumptions are stated explicitly.
Worked example
The calculator opens with a usable example: Home UTC offset = 5.5, Destination UTC offset = -4, Travel direction = west. The live answer above shows what those sample inputs mean. Replace them with your own values to get your result.
Important assumptions and limitations
This is a planning heuristic, not medical advice. Individual sleep and circadian adaptation varies widely.
Results should be treated as a planning aid. Real prices, platform rules, contracts, taxes, institutional policies, technical performance and other conditions can differ from a simplified calculator model.
Pro mode: compare another scenario
Pro mode changes the most decision-relevant driver while keeping the rest of your inputs fixed. This makes it easier to answer questions such as “what if this cost is higher?”, “what if I have less time?” or “what if performance changes?” without rebuilding the whole calculation.
Frequently asked questions
What does the Jet Lag Planner calculate?
Estimate how many days a gradual sleep adjustment might take after crossing time zones.
What formula does the Jet Lag Planner use?
Planning days ≈ absolute time-zone shift ÷ planned sleep shift per day.
What should I enter in the Jet Lag Planner?
Use the examples shown under each field as a guide, then replace every sample value with the numbers from your own situation.
Is the Jet Lag Planner result exact?
This is a planning heuristic, not medical advice. Individual sleep and circadian adaptation varies widely.