What This Calculator Measures

Plan circadian realignment using shift hours, light exposure, and sleep targets.

By combining practical inputs into a structured model, this calculator helps you move from vague estimation to clear planning actions you can execute consistently.

This calculator estimates a daily circadian shift plan.

How to Use This Well

Enter shift hours and days available.
Add light exposure and targets.
Set caffeine cutoff.
Review daily shift target.
Adjust schedule if needed.

Formula Breakdown

Daily shift = shift hours / days

Days needed: shift / daily shift.

Sleep window: bedtime to wake time.

Light: exposure minutes.

Worked Example

3 hour shift over 5 days = 0.6 hr/day.
Sleep window 23:00 to 7:00.
Light exposure 25 minutes.

Interpretation Guide

Range	Meaning	Action
0.5 hr/day	Gentle.	Easy transition.
0.5-1 hr/day	Moderate.	Standard reset.
1-2 hr/day	Fast.	More discipline needed.
2+ hr/day	Aggressive.	Consider extra days.

Optimization Playbook

Increase light: anchor mornings.
Reduce shift speed: add more days.
Align caffeine: cut off earlier.
Use consistent wake time: stabilize rhythm.

Scenario Planning

Baseline: current shift hours.
More days: add 2 days.
More light: add 15 minutes.
Decision rule: keep daily shift under 1 hour.

Common Mistakes to Avoid

Shifting too fast.
Skipping morning light.
Using caffeine too late.
Changing wake time daily.

Implementation Checklist

Set target bedtime.
Plan light exposure.
Adjust caffeine cutoff.
Review progress.

Measurement Notes

Treat this calculator as a directional planning instrument. Output quality improves when your inputs are anchored to recent real data instead of one-off assumptions.

Run multiple scenarios, document what changed, and keep the decision tied to trends, not a single result snapshot.

Circadian Sleep Realign Calculator

Quick Facts

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