The iPhone includes an alarm clock that allows you to set multiple alarms. Each alarm can be set with its own rules that define when the alarm goes off and how often it is repeated. Each alarm can also play its own unique ringtone. When setting an alarm on your iPhone, you can decide whether the alarm supports snooze or not.
You can access your iPhone's alarms in the "Clock" section of the "Utilities" folder. Tap "+" to add a new alarm or tap edit and tap the arrow next to an alarm to edit an alarm. Tap "Snooze" to toggle snooze mode on and off. Tap "Done" when you have finished editing an alarm to save it. A clock icon in the iPhone's status bar indicates that an alarm is scheduled to sound. If no alarm icon appears, ensure that your alarm is set to "On."
If an alarm has snooze enabled, your iPhone will give you the option of postponing the alarm when it goes off. As the alarm is ringing you can put the alarm into snooze mode or turn it off. If you turn the alarm off, it will not sound again until the next time it is scheduled to sound according to the rules that you created while setting the alarm. If you snooze the alarm, the alarm will sound again in ten minutes. You can continue snoozing an alarm indefinitely.
You can snooze your iPhone's alarm by tapping "Snooze" on the screen. Alternatively, you can press your phone's volume or power buttons to snooze the alarm. If your phone is locked, you need to slide your finger across the bottom of the screen to turn the alarm off completely. When your phone is unlocked you can tap "OK" to turn the alarm off completely.
The iPhone does not allow you to customise the default alarm's snooze time or behaviour. If you want increased control over how your alarm snoozes, you can download an alarm app from the iTunes store. Several apps, including Alarm Clock Free, Alarm Clock Pro and A!arm, allow you to set a custom snooze time for your alarm. Other apps, such as Sleep Cycle Alarm Clock, use the iPhone's sensors to monitor your sleep cycles and set a snooze time based on your sleeping habits.