About Sleep Time Reminder

Last updated September 5, 2026.

What we built

Sleep Time Reminder helps you plan a bedtime or wake time around complete sleep cycles. The homepage calculator is ready immediately: choose whether you are planning from a wake time, a bedtime, or right now, compare a few cycle options, and adjust the time you usually need to fall asleep.

We also publish short guides that explain the ideas behind the calculators — sleep cycles, sleep latency, duration ranges, and wake-time planning — in plain language.

What the calculators do and do not do

The calculators use 90-minute intervals as a planning model. They show several times to compare. They do not measure your sleep, detect sleep stages, diagnose conditions, or promise that one time will feel better than another.

Sleep varies night to night. Treat every result as a starting point for a steadier routine, then adjust based on how you feel and what tomorrow requires. If sleep problems persist or affect your days, speak with a qualified health professional.

How we write the guides

Guides are written and reviewed by the Sleep Time Reminder editorial team. We aim for calm, useful explanations — not alarmist language, keyword padding, or medical promises.

• Each guide has one clear question it answers.
• Health-related claims link to current public sources with publication or review dates noted on the page.
• We separate sleep-duration guidance from sleep-cycle timing so readers know which tool fits which question.
• We review guides at least annually or when cited guidance changes materially.

Browse the sleep guides or start with how sleep cycles work.

Privacy and accounts

The calculators work without an account. The only routine preference stored in your browser is your fall-asleep estimate, so the setting can persist between visits on the same device. We do not require sign-in, and we do not treat casual calculator use as a medical record.

Like most websites, the site may use standard analytics to understand which pages are used. We keep that measurement separate from the core calculator flow.

Free today

Sleep Time Reminder is free to use. If we add clearly disclosed advertising or affiliate links later, they will stay secondary to the calculators and guides — never buried in results or disguised as medical advice.