If you own a smartphone, you may have set up a sleep alarm with a snooze function at one point to shorten your sleep duration. And you are not alone.
Truly, many people hit the snooze button on their phones as a daily ritual. But why do so many people hit the snooze button?
A sweeping new study published in Scientific Reports lifts the veil on snooze alarm use through an analysis of more than 3 million sleep sessions.[1]
In this exciting study, Harvard researchers also aim to determine who is likely to snooze and the consequences of this intriguing behavior.
Let's dive in together!
A Background on Sleep and Snooze Alarms
Before we delve into the study, it is crucial to understand the research context.
Sleep is a complicated and dynamic process in the body that keeps us healthy.[2]
The duration and timing of your sleep are influenced by your internal circadian rhythms and the amount of time you spend awake. However, people often repress these biological controls for personal or work reasons.
Typically, experts recommend that adults get 7 to 9 hours of sleep at night.[3] However, in recent decades, a trend of disregarding this advice has been observed among people worldwide, leading to a rise in physical and mental health problems.[4]
After getting sufficient sleep, most people wake up on their own. However, this process can be altered with help, such as using an alarm clock to get up at a particular time, even when one has not had enough sleep.
People who use alarm clocks often have a feature called "snooze" that alerts them at regular intervals after the first sound goes off.
Sleep experts have advised against this behavior. Instead, they recommend setting an alarm for the latest realistic waking time, rather than using a snooze alarm, to achieve as much consolidated, uninterrupted, and high-quality sleep as possible.
Although the use of snooze alarms is quite common, there is a notable lack of research on the effects of their use on sleep and overall health. The limited evidence available suggests that it causes inadequate or poor-quality sleep and feelings of drowsiness upon waking.
The Sleep and Snooze Alarm Use Study
In an impressive study published in Scientific Reports, researchers from Harvard Medical School examined the frequency and characteristics of snooze alarm use among users of a sleep-monitoring smartphone app called SleepCycle.
The substantial database contained six months of data from 21,222 app users and over 3 million sleep sessions from users on four different continents.
The dataset includes users who chose to use the standard snooze feature, reported sleep sessions on 50% or more nights in each month of the monitoring interval, used the app on an iPhone rather than an Android device, and granted permission for their data to be used in research.
Once the first alarm sounds, users can snooze it or turn it off completely. This app's snooze alarm defaults to 5 minutes, but users can alter it in the settings.
The study's findings suggest that the most common snooze alarm duration is 5 minutes (89%), followed by 10 minutes (4%). A user who turned off their first alarm without sleeping had no snoozes that day.
If they choose to snooze, the app will record the number of alarms and the minutes snoozed. If a user disables the snooze alarm before it goes off, the amount of time spent napping is recorded (which is less than the preset duration).
The researchers tracked how frequently and how long users snoozed following each sleep session. Based on these data, the researchers classified the app users into three groups: light, moderate, and heavy snooze alarm users.
They defined heavy snooze alarm users as those who end more than 80% of their sleep sessions with a snooze alarm, moderate users as those who end 40–60% of their sessions with a snooze alarm, and light snooze alarm users as those who end less than 20% of their sessions with a snooze alarm.
Furthermore, the researchers collected data on each user's sleep session. They specifically gathered sleep and wake times for each sleep session.
Sleep and waking times were determined by user activity. When a user starts the app, they are prompted to press 'Start' to begin the process of falling asleep.
The researchers defined 'sleep time' as the user's activity (pressing 'Start'). In the same vein, 'wake time' was defined as the time the initial alarm awakens the user.
They also obtained users' sleep length' from the difference between the previously established sleep and wake timings. Snoozing is not factored into the sleep duration estimates for each sleep session.
The Study's Findings
After analyzing all of the data from the sleep sessions, the result revealed that more than half (55.6%) of them end with a snooze alarm.
Approximately 45% of all users used snooze alarms frequently, while 28% used them moderately, and 27% used them seldom. Some of the other findings include:
- Heavy snooze alarm users had inconsistent sleep and wake times compared to light and moderate users, who used the snooze alarm less frequently and had more consistent sleep times.
- Overall, users snoozed about 2.4 times per day for an average duration of 10.8 minutes. This finding equates to a monthly loss of approximately one 6-hour night of sleep.
- Heavy users set the snooze alarm roughly four times per day, resulting in approximately 20 minutes of dozing time. Light users, on the other hand, used the snooze alarm 1.2 times per day on average, for a total of 3 minutes of napping.
- Snooze alarms were used more frequently during the week (Monday through Friday) than on weekends (Saturday and Sunday). Employees and students may have fewer weekend commitments, which could account for the lower frequency of use.
- Women used their snooze alarms for a lot longer periods than men did. The researchers think this might be because women are more likely to have insomnia, which could be why they use the snooze alarm more often than men. Another reason could be that women have more childcare and housework tasks than men.
- The research population's use of snooze alarms varied very little from month to month. Users in the Northern Hemisphere used snooze alarms slightly more in December and less in September, but users in the Southern Hemisphere did the opposite. The scientists believe these discrepancies may be linked to changes in seasonal sleep patterns resulting from variables such as reduced exposure to natural light during the winter months, which can cause a delay in circadian rhythms.
- Long sleepers (more than 9 hours of sleep) used snooze alarms more frequently than short sleepers (less than 7 hours of sleep) or those getting the recommended amount of sleep (7 to 9 hours). The researchers noted that increased use of snooze alarms during long sleep sessions could indicate hypersomnia or compensatory sleep as a means to recuperate from sleep deprivation.
- The results also showed that sleepers who went to bed later than usual used their snooze alarms more frequently than those who went to bed earlier. The scientists noted that shift workers are more likely to have atypical sleeping times, as they may not have enough time in bed and, therefore, rely more on the snooze alarm. Furthermore, individuals with misaligned sleep patterns may experience more fragmented sleep, leading to a greater reliance on the snooze alarm.
What Does This Mean For Sleep Health?
Although snoozing may feel like a harmless indulgence, experts caution that those precious minutes are often associated with poor sleep quality.
Instead of restorative rest, snoozing may lead to fragmented sleep, leaving us groggier than if we had just gotten up with the first alarm.
Heavy snoozing, particularly after long and erratic sleep sessions, may be a marker of poor sleep health, sleep debt, or circadian misalignment. It could also be due to job demands, such as working shifts, or personal duties, like caring for others, which is especially important given the observed gender gap.
The researchers propose that public health education could help modify sleep behavior. Rather than setting an early alarm and frequently snoozing, people may benefit from setting their alarm for the latest realistic waking time to maximize unbroken sleep.
Final Thoughts
As we increasingly use digital tools to track our health, research like this one highlights the power and potential dangers of our tech-filled lives.
The snooze button may be small, but as this global snapshot reveals, it holds surprising clues to how we sleep, how we live, and how we might do both just a little better.
References
- Robbins, R., Sääf, D., Weaver, M. D., Gradisar, M., Quan, S. F., & Czeisler, C. A. (2025). Snooze alarm use in a global population of smartphone users. Scientific Reports, 15(1), 16942. https://doi.org/10.1038/s41598-025-99563-y
- Baranwal, N., Yu, P. K., & Siegel, N. S. (2023). Sleep physiology, pathophysiology, and sleep hygiene. Progress in cardiovascular diseases, 77, 59–69. https://doi.org/10.1016/j.pcad.2023.02.005
- Watson, N. F., Badr, M. S., Belenky, G., Bliwise, D. L., Buxton, O. M., Buysse, D., Dinges, D. F., Gangwisch, J., Grandner, M. A., Kushida, C., Malhotra, R. K., Martin, J. L., Patel, S. R., Quan, S. F., & Tasali, E. (2015). Recommended Amount of Sleep for a Healthy Adult: A Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep, 38(6), 843–844. https://doi.org/10.5665/sleep.4716
- Chattu, V. K., Manzar, M. D., Kumary, S., Burman, D., Spence, D. W., & Pandi-Perumal, S. R. (2018). The Global Problem of Insufficient Sleep and Its Serious Public Health Implications. Healthcare (Basel, Switzerland), 7(1), 1. https://doi.org/10.3390/healthcare7010001
