Nighty: Sleep Cycle Calculator

Nighty is a calm sleep cycle calculator to help you time your sleep with ease. No tracking, no accounts, no setup — just a simple nightly tool that suggests gentle times to sleep or wake.

Two simple modes

Wake-up mode Know when you need to wake up? Nighty suggests bedtimes aligned with natural sleep cycles.

Bedtime mode Going to sleep now? Nighty shows wake-up times that land near cycle boundaries.

Built around sleep cycles

Sleep typically occurs in ~90-minute cycles. Waking near the end of a cycle can feel easier than waking in the middle of deep sleep.

Nighty suggests times based on this model — a helpful guide, not medical advice.

Accounts for sleep latency

The time it takes you to fall asleep (“sleep latency”) is factored into each calculation.

You can adjust this in Settings if you tend to fall asleep faster or slower than average.

Multiple options, clearly presented

Starting from your chosen time, Nighty shows several cycle options so you can decide what works for your night.

Five cycles (~7.5 hours) are gently highlighted by default as a common full-night duration, but you’re free to choose what fits your schedule.

Simple by design

• Instant answers • No journaling • No sleep tracking hardware • No personal data required

Nighty is built around a single purpose: helping you time your sleep.

Private and offline

All calculations happen on-device. No data is collected.

Thoughtful details

• Calm, night-friendly interface • Subtle, atmospheric animations • Pull to refresh based on the current time • Full support for VoiceOver, Dynamic Type, and Reduce Motion