Focus & Cognitive Performance Planner

How the planner builds your schedule

The planner takes a handful of self-reported inputs — your wake-up time, work hours, bedtime, where meetings usually fall, when you would like to focus, how you take breaks today, your energy in the morning, afternoon and evening, and your main goal — and turns them into a template day at 30-minute resolution.

It works in a fixed order. First it reserves meeting windows inside the day-parts you selected, spreading your weekly meeting hours over five days. Then it places a longer midday break in your lowest-energy slot around lunch. Next it looks for the best positions for deep-work blocks: slots score higher when they fall in a period you prefer and when your self-reported energy is higher, and lower when they sit in a meeting day-part or late in the day. Blocks are 60 or 90 minutes depending on your break pattern and goal, and the planner tries not to place two blocks back to back. The daily total is capped at a conservative three to four hours. After that it fills the lowest-scoring free hour with a batched admin window for email and messages, reserves the last free slot for a shutdown ritual, and marks the rest as flexible shallow work.

Nothing here reads your calendar or measures anything. The output is a suggestion to react to, not a prescription. Edit your answers and the schedule updates.

What the evidence says — and what it does not

Sleep comes first. The clearest result in this whole area is that short sleep degrades attention. A meta-analysis of short-term sleep deprivation studies found large effects on simple attention and vigilance, with smaller but consistent effects on working memory and processing speed A^[2]. A joint consensus of the American Academy of Sleep Medicine and the Sleep Research Society recommends that adults regularly get seven or more hours per night A^[1]. That is why the planner shows your sleep opportunity as a KPI and flags anything under seven hours. If the gap is large, a scheduling tool is the wrong place to start; see Productivity and sleep.

Breaks help a little, reliably. A 2022 systematic review and meta-analysis of micro-breaks found small but consistent benefits for vigour and reduced fatigue, with performance gains mainly on less demanding tasks B^[3]. The planner therefore assumes a 5–10 minute micro-break every 50–90 minutes and one longer midday break, whatever your current habit.

Interruptions cost more than they seem. Receiving a phone notification impaired performance on an attention task even when participants did not touch the phone B^[5]. In a field experiment, people who checked email only three times a day reported lower daily stress than people who checked freely B^[4]. One study found that having your own phone merely visible reduced available working-memory capacity C^[6], but later replications have been mixed, so we present phone removal as a cheap experiment rather than a settled fact.

Switching is not free. Decades of lab work show that changing tasks produces slower and less accurate responses immediately after the switch, and part of that cost persists even with time to prepare A^[8]. Working memory, meanwhile, holds only a few items at a time — roughly three to five chunks when rehearsal is prevented B^[9] — so every open loop competes with the task in front of you. Mental fatigue appears to act as a cost–benefit signal that grows with time on task and pushes you towards easier, more rewarding activities B^[10]. Attention itself is better described as several interacting systems than as a single resource B^[11].

What is weakly supported. Popular productivity advice leans on two ideas the research does not carry well. The claim that work should follow 90-minute "ultradian" cycles is an extrapolation from sleep physiology; there is little direct evidence that 90 minutes is a special length for desk work C. The pomodoro technique has very little direct research behind it either; its 25-minute interval is a convention, not a finding C. We offer 25, 50 and 90-minute sessions because they are practical and people stick to them, not because any one of them is proven. Caffeine timing has better support: a 2016 review summarised that caffeine improves alertness and vigilance, particularly when sleep-restricted, but that late intake can disturb sleep B^[7] — which is why one of the experiments is a cut-off eight hours before bed.

Limitations

• Every input is self-reported; the planner measures nothing and cannot verify your energy, your meetings or your sleep.
• Evidence for exact block lengths is weak. The 25/50/90 options are starting points for your own experiments.
• The "deep-work capacity" cap of three to four hours a day is a planning default drawn from practitioner reports, not a biological limit.
• The energy curve between your three ratings is a simple interpolation, not a prediction.
• Nothing here is medical advice. Persistent fatigue, sleep problems or difficulty concentrating deserve a conversation with a professional.

How to use the result

Try the suggested day for a week without changing anything, and log sessions with the timer. Then run one of the three experiments for two weeks and measure the single thing it names. Keep what helps and drop what does not; the schedule is a hypothesis, and the only data that matters is yours.

Frequently asked questions

How many hours of deep work per day is realistic?

Many experienced knowledge workers report three to four hours of genuinely demanding work a day, which is why the planner caps its suggestion there. The evidence for a hard limit is weak, so treat the cap as a conservative planning default and adjust it from your own logs.

Is the 90-minute block based on ultradian rhythms?

Not really. Ultradian cycles are well described in sleep, but there is little direct evidence that 90 minutes is a special length for desk work. We offer 90 minutes because it is a practical block that fits around meetings; 50 or 25 minutes are equally valid starting points.

Does the pomodoro technique work?

There is very little direct research on the pomodoro technique itself. What is better supported is the general value of short breaks and of reducing task switching. If 25-minute intervals help you start and keep going, that is a good enough reason to use them.

Why does the planner ask about sleep?

Because short sleep has one of the largest and most reliable effects on attention in the whole literature. If your bedtime and wake-up time leave less than seven hours, the planner flags it; under six it suggests looking at sleep before refining your schedule. This is general information, not medical advice.

Where is my data stored?

Only in your browser. Your answers and the timer log are saved in localStorage so they survive a reload; nothing is sent to a server. The share link encodes your answers in the URL and nothing else, and you can clear the session log at any time.

Sources and evidence

1. Recommended Amount of Sleep for a Healthy Adult: A Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society — Watson NF, Badr MS, Belenky G, et al. (2015), consensus statement A doi.org/10.5665/sleep.4716 (retrieved 2026-11-09)
2. A meta-analysis of the impact of short-term sleep deprivation on cognitive variables — Lim J, Dinges DF (2010), meta-analysis A doi.org/10.1037/a0018883 (retrieved 2026-11-09)
3. "Give me a break!" A systematic review and meta-analysis on the efficacy of micro-breaks for increasing well-being and performance — Albulescu P, Macsinga I, Rusu A, et al. (2022), meta-analysis A doi.org/10.1371/journal.pone.0272460 (retrieved 2026-11-09)
4. Checking email less frequently reduces stress — Kushlev K, Dunn EW (2015), field experiment B doi.org/10.1016/j.chb.2014.11.005 (retrieved 2026-11-09)
5. The attentional cost of receiving a cell phone notification — Stothart C, Mitchum A, Yehnert C (2015), experiment B doi.org/10.1037/xhp0000100 (retrieved 2026-11-09)
6. Brain Drain: The Mere Presence of One’s Own Smartphone Reduces Available Cognitive Capacity — Ward AF, Duke K, Gneezy A, Bos MW (2017), experiment (mixed replications) C doi.org/10.1086/691462 (retrieved 2026-11-09)
7. A review of caffeine’s effects on cognitive, physical and occupational performance — McLellan TM, Caldwell JA, Lieberman HR (2016), narrative review A doi.org/10.1016/j.neubiorev.2016.09.001 (retrieved 2026-11-09)
8. Task switching — Monsell S (2003), review A doi.org/10.1016/S1364-6613(03)00028-7 (retrieved 2026-11-09)
9. The Magical Mystery Four: How Is Working Memory Capacity Limited, and Why? — Cowan N (2010), review A doi.org/10.1177/0963721409359277 (retrieved 2026-11-09)
10. Mental fatigue: Costs and benefits — Boksem MAS, Tops M (2008), review B doi.org/10.1016/j.brainresrev.2008.07.001 (retrieved 2026-11-09)
11. The Attention System of the Human Brain — Posner MI, Petersen SE (1990), review A doi.org/10.1146/annurev.ne.13.030190.000325 (retrieved 2026-11-09)