Discover your daily peak hours with simple inputs. Turn alertness scores into an actionable plan. Stay consistent, protect sleep, and finish tasks calmly today.
Set wake time, sleep, habits, and work constraints to estimate peak focus windows.
This planner estimates trends, not medical guidance. If sleep issues persist, consider professional support.
Sample inputs and typical outputs for reference.
| Wake | Sleep | Chronotype | Work | Peak A | Dip | Peak B |
|---|---|---|---|---|---|---|
| 07:00 | 7.5 hr | Intermediate | 08:00–17:00 | 09:30–11:00 | 13:00–14:00 | 15:30–17:00 |
| 06:00 | 8.0 hr | Early | 07:00–16:00 | 08:30–10:00 | 12:00–13:00 | 14:30–16:00 |
| 09:00 | 7.0 hr | Late | 10:00–19:00 | 12:00–13:30 | 15:30–16:30 | 18:00–19:30 |
Your actual peaks depend on light, sleep consistency, and workload.
This calculator combines a circadian rhythm curve with rising sleep pressure, then adjusts for light, screens, meals, and caffeine.
cos(2π · (t − phase) / 24h) gives a daily oscillation.Scores are clamped to 0–100 and optimized in 30-minute steps.
Chronotype sets baseline timing; habits nudge it. Early types shift about 60 minutes earlier and late types about 60 minutes later. Morning outdoor light advances by roughly 30–45 minutes with 20–45 minutes soon after waking. Evening screens delay by about 30–45 minutes when exposure is 2–4 hours. The planner sums these minutes to label your rhythm earlier or later.
Alertness is estimated on a 0–100 scale. A 24‑hour cosine represents circadian variation, anchored near four hours after wake and adjusted by the phase shift. Sleep pressure lowers alertness over ~16 hours awake. The score starts near 60, adds up to 22 from the circadian term, subtracts up to 18 from sleep pressure, and subtracts about 4 per hour of sleep debt.
Across your work interval, the tool scores every 30 minutes to build the table and search for best blocks. Deep work uses your chosen length (30–240 minutes). It selects Peak A, then finds Peak B while avoiding overlap. It also finds the lowest‑energy 60‑minute dip for admin and recovery. A meeting window is chosen where the average score sits near 60.
Servings are scheduled from your first‑dose delay and spaced about three hours apart, but only if they fall before your cutoff ahead of bedtime. Each intake adds a smooth bump that fades over several hours. Meals create a post‑meal dip centered about 75 minutes later. These effects explain why your second peak can shift with timing and cutoff discipline.
The schedule is practical. A warm‑up block appears at the start, followed by Peak A for demanding work. If meeting load is included, collaboration is placed in a stable window, while the dip becomes lunch plus low‑stakes tasks. Peak B reserves a second focus sprint. Optional movement is placed near the end, and a shutdown review closes the day with clear next steps. Export CSV or PDF for sharing.
Scores are directional estimates based on your inputs and typical patterns. Use them to choose better time blocks, then refine using real outcomes like focus quality, errors, and perceived fatigue over a week.
Set wake time to your current schedule and treat the plan as a short-term guide. For rotating shifts, rerun the planner each shift, keep meal timing consistent, and prioritize morning light after waking to stabilize.
Many people feel a natural cortisol rise after waking. Waiting 30–90 minutes can reduce jitter and extend benefits later. Use the delay field to match your tolerance and morning workload.
Yes. Deep work length is adjustable from 30 to 240 minutes. Choose 60–120 minutes for most knowledge work, and use shorter blocks when interruptions are common.
Keep fixed meetings, then use the recommended peaks to protect focus work around them. If meetings land in a peak, shift deep work to the second peak or split into two shorter sprints.
Track one week of planned versus actual performance. Note sleep, light, caffeine, and meal changes, then rerun with updated values. Small shifts, like earlier light or earlier cutoff, often improve both peaks.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.