Coffee or tea can be a pleasure, a pause and part of a routine you value. Caffeine Window helps you explore whether the timing of that habit fits the sleep you want to protect. It uses context from recorded drinks and daily timing to offer planning estimates, while leaving the choice with you.

It shows when a suggested window is open, how much room remains in that window, and how much caffeine the model estimates may remain by your target bedtime. It is a planning tool, not a measurement of caffeine in your blood and not medical advice.

The break may matter as much as the drink

If the afternoon cup gives you a valued pause, changing timing does not have to mean losing that pause. You might keep the conversation, choose another drink or try an earlier moment on some days. Caffeine Window can help explore the timing question while respecting the reason the ritual exists.

What the Caffeine Window can show you

Depending on the shape of your day, AIVELA can create:

• a First Window earlier after waking;
• a Second Window later in the day when timing and sleep context support one;
• a Cutoff before your target bedtime;
• an approximate amount available in the current window, shown in milligrams and whole servings of your primary drink when possible;
• a curve based on the caffeine you actually log today;
• an estimate of caffeine remaining at your target bedtime;
• a separate simulation of your typical caffeine habit.

The window is guidance, not a permission slip. You can always record a drink outside the suggested time or above the suggested amount. AIVELA saves what happened, updates the estimate, and provides light feedback without blocking the entry.

Put the habit in your actual day

Your recorded drinks and relevant sleep timing help place suggestions in context. Keep your target bedtime current and record what you actually consumed. You can then use the view to explore timing choices that fit your plans, rather than follow an abstract ideal day.

An available suggestion is not a quota

You do not need to finish an amount because it appears on screen. The plan does not determine your personal safe dose. Sensitivity, medication and health circumstances can matter, so relevant professional advice takes priority over an App suggestion.

A “cup” is only an estimate

Coffee and tea caffeine content varies with beans or leaves, brew method, serving size, recipe, extra shots, and preparation time. AIVELA's built-in drinks use general serving estimates. A medium café drink in the App cannot know the exact caffeine in the cup in your hand.

Milligrams are therefore the primary value. Whole servings are a convenience. If your usual drink differs meaningfully from the built-in estimate, create a custom drink using trustworthy label or manufacturer information.

Read the estimate with the record behind it

The curve offers a timing estimate from the intake you recorded. It can help you compare choices, but it is not a blood measurement or a complete account of everything that may remain in your body.

Read the date and view, and check whether your log is complete. Real caffeine sensitivity and metabolism differ between people. A low displayed estimate cannot guarantee unaffected sleep or confirm that a dose is suitable for you.

Habit estimate and today's curve are different

The detail page separates two views:

• Habit estimate: a simulation of your typical drinks placed within a typical day;
• Today's curve: an estimate built from today's actual caffeine logs and times.

Keeping them separate prevents a planned morning coffee from looking like one you already consumed. Before interpreting the bedtime estimate, check which view you are reading and whether today's record is complete.

When not to rely on the Caffeine Window

Caffeine Window is intended for adults who already consume caffeinated drinks. It is not designed to encourage a non-user to begin consuming caffeine.

Do not use it to determine a medically safe dose, manage pregnancy or breastfeeding intake, assess a drug interaction, or explain palpitations, anxiety, insomnia, or other symptoms. Follow local health guidance, product labels, and advice from a qualified professional.

If you experience a rapid or irregular heartbeat, severe agitation, vomiting, confusion, a seizure, or another serious symptom after substantial caffeine intake, seek urgent medical help or contact your local poison service.

Use the window to make timing more intentional, not to turn an estimate into a quota.

Related reading

• What Is Calm?
• How AIVELA Detects Sleep and Estimates Sleep Stages
• When Your Sleep Results Look Unusual