Every tool uses peer-reviewed sleep science. Every calculation stays in your browser. Pick one and start sleeping better tonight.
Enter your wake-up time. Get five optimal bedtimes based on 90-minute cycles. No more groggy mornings.
Most PopularTell us your current habits and how you feel. We will recommend a bedtime shift with a realistic plan.
PlanningCalculate the perfect nap length and timing. Avoid sleep inertia with our 10 vs 90-minute guide.
Quick FixLog your sleep and see accumulated debt. Get a realistic repayment plan with charts.
Tracking10-question assessment covering latency, efficiency, and daytime function. See your score.
AssessmentPlan your gradual schedule shift before travel. Export the plan to your calendar.
TravelEvery formula is based on published research from sleep medicine journals, not blog posts.
No accounts. No servers. No data collection. Everything runs in your browser. Clear it anytime.
Every tool generates live Canvas/SVG charts. Save, export, or screenshot them. Not static images.
No wearable? No problem. A pen, paper, and 7 days of patience is all you need to find your natural cycle length.
Deep sleep comes first. REM comes later. Interrupt the order and you wake up feeling like a zombie.
20 minutes or 90 minutes. Nothing in between. Here is the exact science of napping without grogginess.
One app said I got 8.2 hours. Another said 6.4. I wore a polysomnography headband to find the truth.
Start adjusting three days before your flight. Here is the exact light exposure schedule for east vs west travel.
I napped for 90 minutes every day for a month. Then I tried 20 minutes. The data was shocking.