Sleep can transform our lives.
Our lives can transform sleep.

A third of people in developed nations – and close to 40% of Japanese – are concerned about their sleeping
patterns. In Japan alone, lack of sleep is estimated to cost the economy ¥3.5 trillion yen [each year],
with ¥3.2 trillion of this attributable to the resulting decline in productivity.
Many people do not realize that a lack of sleep is having a negative impact on their performance.
Sleepdays helps you to restore your performance to its former glory.


Download here!

A World First:
Introducing the
Circadian Sleep™ Method.

A Groundbreaking Method That Fuses Somnology* and Chronobiology
When our circadian rhythm (internal clock) is disrupted, we experience not only a reduction in the quality of our sleep, but also a decline in our performance throughout the day. Disruptions can also impact our efficiency at work, diet, and efforts to improve our physical condition. The Circadian Sleep™ Method analyses your circadian rhythm through your sleeping patterns, and makes recommendations throughout the day on how best to time your activities. These recommendations support you in restoring your circadian rhythm to a healthy state. Informed lifestyle decisions throughout the day lead to high quality sleep, and high quality sleep leads to an increase in the quality of your performance throughout the day.

  • RHYTHM 01



  • RHYTHM 02



  • RHYTHM 03


    Intellectual task Time

  • RHYTHM 04



  • RHYTHM 05



  • RHYTHM 06


    Idea Time

  • RHYTHM 07


    High Performance Time

  • RHYTHM 08



  • RHYTHM 09


    Workout Time

  • RHYTHM 10


    Reset Hour

  • RHYTHM 11



  • RHYTHM 12



Know Yourself.

Not just by analyzing your sleep every day,
but also by understanding your habits.

Sleep Analysis
By unique analysis algorithms, Sleepdays is capable of assessing the quality of your sleep to a high level of accuracy. It also allows you to examine the finer details of this analysis, such as time taken to fall asleep and sleep efficiency.
Rhythm Check
Circadian rhythms cannot be understood in a single day. Through continuous daily use, Sleepdays allows you to identify the characteristics of your own circadian rhythm, as well as any irregularities in your internal clock.

Unlock Your True Potential.

Unlock your true potential by acting on lifestyle recommendations provided by in-app notifications.

Lifestyle Recommendations
Sleepdays uses sleep analysis to make recommendations on activity timing that are tailored specifically to you. In addition to recommendations on basic activities such as eating, taking a bath, and going to bed, Sleepdays also allows you to determine the optimal times to take full advantage of your capabilities, allowing you to harness your creativity in conceiving innovative ideas or maximize your physical performance when exercising.
Algorithms developed independently by TWO. *Development overseen by Hideyuki Negoro, MD, PhD

Hideyuki Negoro, MD, PhD

Doctor Negoro has held a number of [highly respected] positions, including Associate Professor at the Harvard University Medical Faculty and the University of Paris Medical Faculty; Board Member and Professor at the Graduate School of Project Design; Clinical Professor at Tokyo Medical and Dental University; Internal Medicine Specialist at the Japanese Society of Internal Medicine; and Advisor on Japan at the American Academy of Anti-Aging Medicine.
Doctor Negoro’s specializations include internal medicine, anti-aging medicine, gene-therapy, longevity gene-therapy, and aesthetic internal medicine.

Nap Timer
A nap in the early afternoon has numerous positive effects, including improved memory and enhanced productivity. Sleepdays allows you to take a leisurely nap by setting a custom timer; a 30-minute nap leads to a comfortable and productive afternoon.

Optimize Your Sleep

Your “reset hours” start two hours before you go to bed.
Use this time to ready your mind and body for sleep.

Sleep Sounds
Sleep Sounds is a collection of healing music to relax your mind. Sleepdays is preinstalled with Sleep Sounds to suit a range of situations.
Breathing Techniques
Relax your mind and body by using breathing techniques. Relaxing your whole body helps you to drift off more easily.

How to use

The Accumulation of Blissful Sleep
and Rewarding Days

The day doesn’t end when you go to sleep – it begins.
Through the accumulation of high quality sleep and fulfilling activities throughout the day,
everyday life just gets better and better.