Even though using the snooze function on an alarm clock isn’t recommended by sleep experts, it’s a common practice, according to a new study led by researchers at Mass General Brigham. Using data from the sleep analysis app Sleep Cycle, researchers analyzed sleep data from more than 21,000 people around the world. The snooze button was pressed in close to 56% of the 3 million nights studied. Around 45% of study subjects hit the snooze button on more than 80% of mornings. These heavy users snoozed, on average, 20 minutes a day. Results are published in Scientific Reports.

“Many of us hit the snooze alarm in the morning with the hope of getting a ‘little more sleep,’ but this widely practiced phenomenon has received little attention in sleep research. In a global sample we found that more than half of sleep sessions end in a snooze alarm, and users spent an average of 11 minutes in between snooze alarms each morning before waking,” said lead author Rebecca Robbins, PhD, in the Division of Sleep and Circadian Disorders Medicine at Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system.

Reliance upon snooze varied by day of the week, with more snooze alarm during the typical work week (Monday through Friday) with the lowest snooze alarm utilization on Saturday and Sunday mornings.

Snooze alarm utilization was lower among those sleeping five or fewer hours. According to the researchers, this could be because short sleepers are cutting sleep short due to occupational responsibilities, which would require them to wake up and start their day, leaving little time for a snooze. Heavy users of the snooze alarm (those relying on snooze alarm on more than 80% of mornings studied) spent on average 20 minutes in between snooze alarms. Heavy snooze alarm users also demonstrated more erratic sleep schedules than other categories of users.

People in the U.S., Sweden and Germany had the highest snooze button use, while those living in Japan and Australia had the lowest.

“Unfortunately, the snooze alarm disrupts some of the most important stages of sleep,” said Robbins. “The hours just before waking are rich in rapid eye movement sleep. Hitting the snooze alarm will interrupt these critical stages of sleep and typically only offer you light sleep in between snooze alarms. The best approach for optimizing your sleep and next day performance is to set your alarm for the latest possible time, then commit to getting out of bed when your first alarm goes off.”