Snooze alarms: first alarm or get-up time?

Two mornings that share a label

Consider two hypothetical alarm setups. Both involve a half-hour between the first alarm and getting out of bed, but they change different parts of the morning.

• Earlier first alarm: the clock first sounds at 6:30 a.m., repeats afterward, and you get up at 7:00. The alarm sequence begins before a fixed get-up time.
• Later get-up: the clock first sounds at 7:00 a.m., you postpone getting up, and leave bed at 7:30. The morning starts later than the first alarm.

Calling both arrangements 30 minutes of snoozing hides that difference. It leaves a second question: how much of that interval was actually spent asleep?

A large app study describes a habit

Published May 19, 2025, a retrospective study examined 3,017,276 sessions from 21,222 selected SleepCycle iPhone users. Snooze occurred in 55.6% of sessions. Ages were unavailable. (2025 app study)

These were app records, not laboratory sleep measurements. The app counted sleep duration from Start to first alarm; researchers could not confirm sleep between alarms or assess morning grogginess. Frequency cannot establish benefit or harm. (2025 app study)

Two coauthors were affiliated with SleepCycle, including one disclosed employee; other commercial relationships were reported. No separate study-funding statement was identified. (2025 app study)

A controlled experiment asked a different question

First published October 17, 2023, the experiment compared snooze and no-snooze conditions in 31 young habitual snoozers, varying their order. Final waking time stayed fixed; snoozing began 30 minutes earlier. Laboratory-recorded median sleep during that half-hour was 23 minutes with snoozing versus 29 without. Some immediate cognitive tests favored snoozing; others did not. Evidence strength varied. (2023 alarm experiment)

One night per condition cannot establish long-term effects. Stockholm University's Stress Research Institute and the Swedish Research Council funded it; authors declared no conflicts. (2023 alarm experiment)

Give the alarm a specific job

For your own setup, start with the event the clock must serve. A departure time is not a first-alarm time, and an appointment is not a get-up time. Work backward through the actual morning tasks before choosing the number on the clock.

For example, a 7:40 departure with 40 minutes needed to get ready puts getting out of bed at 7:00. Whether a first alarm sounds before 7:00 or at 7:00 is a separate choice. This arithmetic does not predict how rested or alert you will feel; it makes the timing decision explicit.

• Name the first alarm's purpose: a signal to leave bed, or the start of an intended alarm sequence.
• Name the time you need to be out of bed, separately from the time the phone first makes noise.
• When changing the setup, identify which time is moving. An earlier first alarm and a later get-up are different changes.

Read the comparison

Ask which alarm changed before applying a snooze headline to your morning.