Added in API level 1

Summary: Nested Classes | Constants | Methods | Inherited Methods

AlarmManager

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Kotlin |Java

public class AlarmManager
extends Object

java.lang.Object
↳	android.app.AlarmManager

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This class provides access to the system alarm services. These allow you to schedule your application to be run at some point in the future. When an alarm goes off, the Intent that had been registered for it is broadcast by the system, automatically starting the target application if it is not already running. Registered alarms are retained while the device is asleep (and can optionally wake the device up if they go off during that time), but will be cleared if it is turned off and rebooted.

The Alarm Manager holds a CPU wake lock as long as the alarm receiver's onReceive() method is executing. This guarantees that the phone will not sleep until you have finished handling the broadcast. Once onReceive() returns, the Alarm Manager releases this wake lock. This means that the phone will in some cases sleep as soon as your onReceive() method completes. If your alarm receiver called Context.startService(), it is possible that the phone will sleep before the requested service is launched. To prevent this, your BroadcastReceiver and Service will need to implement a separate wake lock policy to ensure that the phone continues running until the service becomes available.

Note: The Alarm Manager is intended for cases where you want to have your application code run at a specific time, even if your application is not currently running. For normal timing operations (ticks, timeouts, etc) it is easier and much more efficient to use Handler.

Note: Beginning with API 19 (Build.VERSION_CODES.KITKAT) alarm delivery is inexact: the OS will shift alarms in order to minimize wakeups and battery use. There are new APIs to support applications which need strict delivery guarantees; see setWindow(int, long, long, android.app.PendingIntent) and setExact(int, long, android.app.PendingIntent). Applications whose targetSdkVersion is earlier than API 19 will continue to see the previous behavior in which all alarms are delivered exactly when requested.

Summary

Nested classes
class	AlarmManager.AlarmClockInfo An immutable description of a scheduled "alarm clock" event.
interface	AlarmManager.OnAlarmListener Direct-notification alarms: the requester must be running continuously from the time the alarm is set to the time it is delivered, or delivery will fail.

Constants
String	ACTION_NEXT_ALARM_CLOCK_CHANGED Broadcast Action: Sent after the value returned by getNextAlarmClock() has changed.
String	ACTION_SCHEDULE_EXACT_ALARM_PERMISSION_STATE_CHANGED Broadcast Action: An app is granted the Manifest.permission.SCHEDULE_EXACT_ALARM permission.
int	ELAPSED_REALTIME Alarm time in SystemClock.elapsedRealtime() (time since boot, including sleep).
int	ELAPSED_REALTIME_WAKEUP Alarm time in SystemClock.elapsedRealtime() (time since boot, including sleep), which will wake up the device when it goes off.
long	INTERVAL_DAY Available inexact recurrence interval recognized by setInexactRepeating(int, long, long, android.app.PendingIntent) when running on Android prior to API 19.
long	INTERVAL_FIFTEEN_MINUTES Available inexact recurrence interval recognized by setInexactRepeating(int, long, long, android.app.PendingIntent) when running on Android prior to API 19.
long	INTERVAL_HALF_DAY Available inexact recurrence interval recognized by setInexactRepeating(int, long, long, android.app.PendingIntent) when running on Android prior to API 19.
long	INTERVAL_HALF_HOUR Available inexact recurrence interval recognized by setInexactRepeating(int, long, long, android.app.PendingIntent) when running on Android prior to API 19.
long	INTERVAL_HOUR Available inexact recurrence interval recognized by setInexactRepeating(int, long, long, android.app.PendingIntent) when running on Android prior to API 19.
int	RTC Alarm time in System.currentTimeMillis() (wall clock time in UTC).
int	RTC_WAKEUP Alarm time in System.currentTimeMillis() (wall clock time in UTC), which will wake up the device when it goes off.

Public methods
boolean	canScheduleExactAlarms() Called to check if the caller can schedule exact alarms.
void	cancel(PendingIntent operation) Remove any alarms with a matching Intent.
void	cancel(AlarmManager.OnAlarmListener listener) Remove any alarm scheduled to be delivered to the given OnAlarmListener.
void	cancelAll() Remove all alarms previously set by the caller, if any.
AlarmManager.AlarmClockInfo	getNextAlarmClock() Gets information about the next alarm clock currently scheduled.
void	set(int type, long triggerAtMillis, PendingIntent operation) Schedule an alarm.
void	set(int type, long triggerAtMillis, String tag, AlarmManager.OnAlarmListener listener, Handler targetHandler) Direct callback version of set(int, long, android.app.PendingIntent).
void	setAlarmClock(AlarmManager.AlarmClockInfo info, PendingIntent operation) Schedule an alarm that represents an alarm clock, which will be used to notify the user when it goes off.
void	setAndAllowWhileIdle(int type, long triggerAtMillis, PendingIntent operation) Like set(int, long, android.app.PendingIntent), but this alarm will be allowed to execute even when the system is in low-power idle (a.k.a.
void	setExact(int type, long triggerAtMillis, PendingIntent operation) Schedule an alarm to be delivered precisely at the stated time.
void	setExact(int type, long triggerAtMillis, String tag, AlarmManager.OnAlarmListener listener, Handler targetHandler) Direct callback version of setExact(int, long, android.app.PendingIntent).
void	setExactAndAllowWhileIdle(int type, long triggerAtMillis, PendingIntent operation) Like setExact(int, long, android.app.PendingIntent), but this alarm will be allowed to execute even when the system is in low-power idle modes.
void	setInexactRepeating(int type, long triggerAtMillis, long intervalMillis, PendingIntent operation) Schedule a repeating alarm that has inexact trigger time requirements; for example, an alarm that repeats every hour, but not necessarily at the top of every hour.
void	setRepeating(int type, long triggerAtMillis, long intervalMillis, PendingIntent operation) Schedule a repeating alarm.
void	setTime(long millis) Set the system wall clock time.
void	setTimeZone(String timeZone) Sets the system's persistent default time zone.
void	setWindow(int type, long windowStartMillis, long windowLengthMillis, PendingIntent operation) Schedule an alarm to be delivered within a given window of time.
void	setWindow(int type, long windowStartMillis, long windowLengthMillis, String tag, AlarmManager.OnAlarmListener listener, Handler targetHandler) Direct callback version of setWindow(int, long, long, android.app.PendingIntent).
void	setWindow(int type, long windowStartMillis, long windowLengthMillis, String tag, Executor executor, AlarmManager.OnAlarmListener listener) Direct callback version of setWindow(int, long, long, android.app.PendingIntent).

Inherited methods

From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long timeoutMillis, int nanos) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait(long timeoutMillis) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait() Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Constants

ACTION_NEXT_ALARM_CLOCK_CHANGED

Added in API level 21

public static final String ACTION_NEXT_ALARM_CLOCK_CHANGED

Broadcast Action: Sent after the value returned by getNextAlarmClock() has changed.

This is a protected intent that can only be sent by the system. It is only sent to registered receivers.

Constant Value: "android.app.action.NEXT_ALARM_CLOCK_CHANGED"

ACTION_SCHEDULE_EXACT_ALARM_PERMISSION_STATE_CHANGED

Added in API level 31

public static final String ACTION_SCHEDULE_EXACT_ALARM_PERMISSION_STATE_CHANGED

Broadcast Action: An app is granted the Manifest.permission.SCHEDULE_EXACT_ALARM permission.

When the user revokes the Manifest.permission.SCHEDULE_EXACT_ALARM permission, all alarms scheduled with setExact(int, long, PendingIntent), setExactAndAllowWhileIdle(int, long, PendingIntent) and setAlarmClock(android.app.AlarmManager.AlarmClockInfo, android.app.PendingIntent) will be deleted.

When the user grants the Manifest.permission.SCHEDULE_EXACT_ALARM, this broadcast will be sent. Applications can reschedule all the necessary alarms when receiving it.

This broadcast will not be sent when the user revokes the permission.

Note: Applications are still required to check canScheduleExactAlarms() before using the above APIs after receiving this broadcast, because it's possible that the permission is already revoked again by the time applications receive this broadcast.

This broadcast will be sent to both runtime receivers and manifest receivers.

This broadcast is sent as a foreground broadcast. See Intent.FLAG_RECEIVER_FOREGROUND.

When an application receives this broadcast, it's allowed to start a foreground service.

Constant Value: "android.app.action.SCHEDULE_EXACT_ALARM_PERMISSION_STATE_CHANGED"

ELAPSED_REALTIME

Added in API level 1

public static final int ELAPSED_REALTIME

Alarm time in SystemClock.elapsedRealtime() (time since boot, including sleep). This alarm does not wake the device up; if it goes off while the device is asleep, it will not be delivered until the next time the device wakes up.

Constant Value: 3 (0x00000003)

ELAPSED_REALTIME_WAKEUP

Added in API level 1

public static final int ELAPSED_REALTIME_WAKEUP

Alarm time in SystemClock.elapsedRealtime() (time since boot, including sleep), which will wake up the device when it goes off.

Constant Value: 2 (0x00000002)

INTERVAL_DAY

Added in API level 3

public static final long INTERVAL_DAY

Available inexact recurrence interval recognized by setInexactRepeating(int, long, long, android.app.PendingIntent) when running on Android prior to API 19.

Constant Value: 86400000 (0x0000000005265c00)

INTERVAL_FIFTEEN_MINUTES

Added in API level 3

public static final long INTERVAL_FIFTEEN_MINUTES

Available inexact recurrence interval recognized by setInexactRepeating(int, long, long, android.app.PendingIntent) when running on Android prior to API 19.

Constant Value: 900000 (0x00000000000dbba0)

INTERVAL_HALF_DAY

Added in API level 3

public static final long INTERVAL_HALF_DAY

Available inexact recurrence interval recognized by setInexactRepeating(int, long, long, android.app.PendingIntent) when running on Android prior to API 19.

Constant Value: 43200000 (0x0000000002932e00)

INTERVAL_HALF_HOUR

Added in API level 3

public static final long INTERVAL_HALF_HOUR

Available inexact recurrence interval recognized by setInexactRepeating(int, long, long, android.app.PendingIntent) when running on Android prior to API 19.

Constant Value: 1800000 (0x00000000001b7740)

INTERVAL_HOUR

Added in API level 3

public static final long INTERVAL_HOUR

Available inexact recurrence interval recognized by setInexactRepeating(int, long, long, android.app.PendingIntent) when running on Android prior to API 19.

Constant Value: 3600000 (0x000000000036ee80)

RTC

Added in API level 1

public static final int RTC

Alarm time in System.currentTimeMillis() (wall clock time in UTC). This alarm does not wake the device up; if it goes off while the device is asleep, it will not be delivered until the next time the device wakes up.

Constant Value: 1 (0x00000001)

RTC_WAKEUP

Added in API level 1

public static final int RTC_WAKEUP

Alarm time in System.currentTimeMillis() (wall clock time in UTC), which will wake up the device when it goes off.

Constant Value: 0 (0x00000000)

Public methods

canScheduleExactAlarms

Added in API level 31

public boolean canScheduleExactAlarms ()

Called to check if the caller can schedule exact alarms. Your app schedules exact alarms when it calls any of the setExact... or setAlarmClock API methods.

Apps targeting Build.VERSION_CODES#S or higher can schedule exact alarms only if they have the Manifest.permission#SCHEDULE_EXACT_ALARM permission or they are on the device's power-save exemption list. These apps can also start Settings.ACTION_REQUEST_SCHEDULE_EXACT_ALARM to request this permission from the user.

Apps targeting lower sdk versions, can always schedule exact alarms.

Returns
boolean	true if the caller can schedule exact alarms, false otherwise.

See also:

• Settings.ACTION_REQUEST_SCHEDULE_EXACT_ALARM
• setExact(int, long, PendingIntent)
• setExactAndAllowWhileIdle(int, long, PendingIntent)
• setAlarmClock(AlarmClockInfo, PendingIntent)
• PowerManager.isIgnoringBatteryOptimizations(String)

cancel

Added in API level 1

public void cancel (PendingIntent operation)

Remove any alarms with a matching Intent. Any alarm, of any type, whose Intent matches this one (as defined by Intent#filterEquals), will be canceled.

Parameters
operation	PendingIntent: IntentSender which matches a previously added IntentSender. This parameter must not be null.

See also:

• set(int, long, PendingIntent)

cancel

Added in API level 24

public void cancel (AlarmManager.OnAlarmListener listener)

Remove any alarm scheduled to be delivered to the given OnAlarmListener.

Parameters
listener	AlarmManager.OnAlarmListener: OnAlarmListener instance that is the target of a currently-set alarm. This value cannot be null.

cancelAll

Added in API level 34

public void cancelAll ()

Remove all alarms previously set by the caller, if any.

getNextAlarmClock

Added in API level 21

public AlarmManager.AlarmClockInfo getNextAlarmClock ()

Gets information about the next alarm clock currently scheduled. The alarm clocks considered are those scheduled by any application using the setAlarmClock(AlarmClockInfo, PendingIntent) method.

Returns
AlarmManager.AlarmClockInfo	An AlarmClockInfo object describing the next upcoming alarm clock event that will occur. If there are no alarm clock events currently scheduled, this method will return null.

See also:

• setAlarmClock(AlarmClockInfo, PendingIntent)
• AlarmManager.AlarmClockInfo
• ACTION_NEXT_ALARM_CLOCK_CHANGED

set

Added in API level 1

public void set (int type, 
                long triggerAtMillis, 
                PendingIntent operation)

Schedule an alarm. Note: for timing operations (ticks, timeouts, etc) it is easier and much more efficient to use Handler. If there is already an alarm scheduled for the same IntentSender, that previous alarm will first be canceled.

If the stated trigger time is in the past, the alarm will be triggered immediately. If there is already an alarm for this Intent scheduled (with the equality of two intents being defined by Intent#filterEquals), then it will be removed and replaced by this one.

The alarm is an Intent broadcast that goes to a broadcast receiver that you registered with Context.registerReceiver(BroadcastReceiver, IntentFilter) or through the <receiver> tag in an AndroidManifest.xml file.

Alarm intents are delivered with a data extra of type int called Intent.EXTRA_ALARM_COUNT that indicates how many past alarm events have been accumulated into this intent broadcast. Recurring alarms that have gone undelivered because the phone was asleep may have a count greater than one when delivered.

Note: Beginning in API 19, the trigger time passed to this method is treated as inexact: the alarm will not be delivered before this time, but may be deferred and delivered some time later. The OS will use this policy in order to "batch" alarms together across the entire system, minimizing the number of times the device needs to "wake up" and minimizing battery use. In general, alarms scheduled in the near future will not be deferred as long as alarms scheduled far in the future.

With the new batching policy, delivery ordering guarantees are not as strong as they were previously. If the application sets multiple alarms, it is possible that these alarms' actual delivery ordering may not match the order of their requested delivery times. If your application has strong ordering requirements there are other APIs that you can use to get the necessary behavior; see setWindow(int, long, long, android.app.PendingIntent) and setExact(int, long, android.app.PendingIntent).

Applications whose targetSdkVersion is before API 19 will continue to get the previous alarm behavior: all of their scheduled alarms will be treated as exact.

Parameters
type	int: type of alarm. Value is RTC_WAKEUP, RTC, ELAPSED_REALTIME_WAKEUP, or ELAPSED_REALTIME
triggerAtMillis	long: time in milliseconds that the alarm should go off, using the appropriate clock (depending on the alarm type).
operation	PendingIntent: Action to perform when the alarm goes off; typically comes from IntentSender.getBroadcast(). This value cannot be null.

See also:

• Handler
• setExact(int, long, PendingIntent)
• setRepeating(int, long, long, PendingIntent)
• setWindow(int, long, long, PendingIntent)
• cancel(OnAlarmListener)
• Context.sendBroadcast(Intent)
• Context.registerReceiver(BroadcastReceiver, IntentFilter)
• Intent.filterEquals(Intent)
• ELAPSED_REALTIME
• ELAPSED_REALTIME_WAKEUP
• RTC
• RTC_WAKEUP

set

Added in API level 24

public void set (int type, 
                long triggerAtMillis, 
                String tag, 
                AlarmManager.OnAlarmListener listener, 
                Handler targetHandler)

Direct callback version of set(int, long, android.app.PendingIntent). Rather than supplying a PendingIntent to be sent when the alarm time is reached, this variant supplies an OnAlarmListener instance that will be invoked at that time.

The OnAlarmListener's onAlarm() method will be invoked via the specified target Handler, or on the application's main looper if null is passed as the targetHandler parameter.

Parameters
type	int: type of alarm. Value is RTC_WAKEUP, RTC, ELAPSED_REALTIME_WAKEUP, or ELAPSED_REALTIME
triggerAtMillis	long: time in milliseconds that the alarm should go off, using the appropriate clock (depending on the alarm type).
tag	String: string describing the alarm, used for logging and battery-use attribution This value may be null.
listener	AlarmManager.OnAlarmListener: OnAlarmListener instance whose onAlarm() method will be called when the alarm time is reached. A given OnAlarmListener instance can only be the target of a single pending alarm, just as a given PendingIntent can only be used with one alarm at a time. This value cannot be null.
targetHandler	Handler: Handler on which to execute the listener's onAlarm() callback, or null to run that callback on the main looper.

setAlarmClock

Added in API level 21

public void setAlarmClock (AlarmManager.AlarmClockInfo info, 
                PendingIntent operation)

Schedule an alarm that represents an alarm clock, which will be used to notify the user when it goes off. The expectation is that when this alarm triggers, the application will further wake up the device to tell the user about the alarm -- turning on the screen, playing a sound, vibrating, etc. As such, the system will typically also use the information supplied here to tell the user about this upcoming alarm if appropriate.

Due to the nature of this kind of alarm, similar to setExactAndAllowWhileIdle(int, long, PendingIntent), these alarms will be allowed to trigger even if the system is in a low-power idle (a.k.a. doze) mode. The system may also do some prep-work when it sees that such an alarm coming up, to reduce the amount of background work that could happen if this causes the device to fully wake up -- this is to avoid situations such as a large number of devices having an alarm set at the same time in the morning, all waking up at that time and suddenly swamping the network with pending background work. As such, these types of alarms can be extremely expensive on battery use and should only be used for their intended purpose.

This method is like setExact(int, long, android.app.PendingIntent), but implies RTC_WAKEUP.

Note: Starting with Build.VERSION_CODES#S, apps targeting SDK level 31 or higher need to request the SCHEDULE_EXACT_ALARM permission to use this API. The user and the system can revoke this permission via the special app access screen in Settings.

Note: Exact alarms should only be used for user-facing features. For more details, see Exact alarm permission.

Alarms scheduled via this API will be allowed to start a foreground service even if the app is in the background.
Requires Manifest.permission.SCHEDULE_EXACT_ALARM

Parameters
info	AlarmManager.AlarmClockInfo: This value cannot be null.
operation	PendingIntent: Action to perform when the alarm goes off; typically comes from IntentSender.getBroadcast(). This value cannot be null.

See also:

• set(int, long, PendingIntent)
• setRepeating(int, long, long, PendingIntent)
• setWindow(int, long, long, PendingIntent)
• setExact(int, long, PendingIntent)
• cancel(OnAlarmListener)
• getNextAlarmClock()
• Context.sendBroadcast(Intent)
• Context.registerReceiver(BroadcastReceiver, IntentFilter)
• Intent.filterEquals(Intent)
• SCHEDULE_EXACT_ALARM

setAndAllowWhileIdle

Added in API level 23

public void setAndAllowWhileIdle (int type, 
                long triggerAtMillis, 
                PendingIntent operation)

Like set(int, long, android.app.PendingIntent), but this alarm will be allowed to execute even when the system is in low-power idle (a.k.a. doze) modes. This type of alarm must only be used for situations where it is actually required that the alarm go off while in idle -- a reasonable example would be for a calendar notification that should make a sound so the user is aware of it. When the alarm is dispatched, the app will also be added to the system's temporary power exemption list for approximately 10 seconds to allow that application to acquire further wake locks in which to complete its work.

These alarms can significantly impact the power use of the device when idle (and thus cause significant battery blame to the app scheduling them), so they should be used with care. To reduce abuse, there are restrictions on how frequently these alarms will go off for a particular application. Under normal system operation, it will not dispatch these alarms more than about every minute (at which point every such pending alarm is dispatched); when in low-power idle modes this duration may be significantly longer, such as 15 minutes.

Unlike other alarms, the system is free to reschedule this type of alarm to happen out of order with any other alarms, even those from the same app. This will clearly happen when the device is idle (since this alarm can go off while idle, when any other alarms from the app will be held until later), but may also happen even when not idle.

Regardless of the app's target SDK version, this call always allows batching of the alarm.

Parameters
type	int: type of alarm. Value is RTC_WAKEUP, RTC, ELAPSED_REALTIME_WAKEUP, or ELAPSED_REALTIME
triggerAtMillis	long: time in milliseconds that the alarm should go off, using the appropriate clock (depending on the alarm type).
operation	PendingIntent: Action to perform when the alarm goes off; typically comes from IntentSender.getBroadcast(). This value cannot be null.

See also:

• set(int, long, PendingIntent)
• setExactAndAllowWhileIdle(int, long, PendingIntent)
• cancel(OnAlarmListener)
• Context.sendBroadcast(Intent)
• Context.registerReceiver(BroadcastReceiver, IntentFilter)
• Intent.filterEquals(Intent)
• ELAPSED_REALTIME
• ELAPSED_REALTIME_WAKEUP
• RTC
• RTC_WAKEUP

setExact

Added in API level 19

public void setExact (int type, 
                long triggerAtMillis, 
                PendingIntent operation)

Schedule an alarm to be delivered precisely at the stated time.

This method is like set(int, long, android.app.PendingIntent), but does not permit the OS to adjust the delivery time. The alarm will be delivered as nearly as possible to the requested trigger time.

Note: only alarms for which there is a strong demand for exact-time delivery (such as an alarm clock ringing at the requested time) should be scheduled as exact. Applications are strongly discouraged from using exact alarms unnecessarily as they reduce the OS's ability to minimize battery use.

Note: Starting with Build.VERSION_CODES#S, apps targeting SDK level 31 or higher need to request the SCHEDULE_EXACT_ALARM permission to use this API, unless the app is exempt from battery restrictions. The user and the system can revoke this permission via the special app access screen in Settings.

Note: Exact alarms should only be used for user-facing features. For more details, see Exact alarm permission.

Parameters
type	int: type of alarm. Value is RTC_WAKEUP, RTC, ELAPSED_REALTIME_WAKEUP, or ELAPSED_REALTIME
triggerAtMillis	long: time in milliseconds that the alarm should go off, using the appropriate clock (depending on the alarm type).
operation	PendingIntent: Action to perform when the alarm goes off; typically comes from IntentSender.getBroadcast(). This value cannot be null.

See also:

• set(int, long, PendingIntent)
• setRepeating(int, long, long, PendingIntent)
• setWindow(int, long, long, PendingIntent)
• cancel(OnAlarmListener)
• Context.sendBroadcast(Intent)
• Context.registerReceiver(BroadcastReceiver, IntentFilter)
• Intent.filterEquals(Intent)
• ELAPSED_REALTIME
• ELAPSED_REALTIME_WAKEUP
• RTC
• RTC_WAKEUP
• SCHEDULE_EXACT_ALARM

setExact

Added in API level 24

public void setExact (int type, 
                long triggerAtMillis, 
                String tag, 
                AlarmManager.OnAlarmListener listener, 
                Handler targetHandler)

Direct callback version of setExact(int, long, android.app.PendingIntent). Rather than supplying a PendingIntent to be sent when the alarm time is reached, this variant supplies an OnAlarmListener instance that will be invoked at that time.

The OnAlarmListener's onAlarm() method will be invoked via the specified target Handler, or on the application's main looper if null is passed as the targetHandler parameter.

This API should only be used to set alarms that are relevant in the context of the app's current lifecycle, as the OnAlarmListener instance supplied is only valid as long as the process is alive, and the system can clean up the app process as soon as it is out of lifecycle. To schedule alarms that fire reliably even after the current lifecycle completes, and wakes up the app if required, use any of the other scheduling APIs that accept a PendingIntent instance.

On previous android versions Build.VERSION_CODES#S and Build.VERSION_CODES#TIRAMISU, apps targeting SDK level 31 or higher needed to hold the SCHEDULE_EXACT_ALARM permission to use this API, unless the app was exempt from battery restrictions.

Note: Starting with android version Build.VERSION_CODES#UPSIDE_DOWN_CAKE, the system will explicitly drop any alarms set via this API when the calling app goes out of lifecycle.

Parameters
type	int: Value is RTC_WAKEUP, RTC, ELAPSED_REALTIME_WAKEUP, or ELAPSED_REALTIME
triggerAtMillis	long
tag	String: This value may be null.
listener	AlarmManager.OnAlarmListener: This value cannot be null.
targetHandler	Handler: This value may be null.

setExactAndAllowWhileIdle

Added in API level 23

public void setExactAndAllowWhileIdle (int type, 
                long triggerAtMillis, 
                PendingIntent operation)

Like setExact(int, long, android.app.PendingIntent), but this alarm will be allowed to execute even when the system is in low-power idle modes. If you don't need exact scheduling of the alarm but still need to execute while idle, consider using setAndAllowWhileIdle(int, long, PendingIntent). This type of alarm must only be used for situations where it is actually required that the alarm go off while in idle -- a reasonable example would be for a calendar notification that should make a sound so the user is aware of it. When the alarm is dispatched, the app will also be added to the system's temporary power exemption list for approximately 10 seconds to allow that application to acquire further wake locks in which to complete its work.

These alarms can significantly impact the power use of the device when idle (and thus cause significant battery blame to the app scheduling them), so they should be used with care. To reduce abuse, there are restrictions on how frequently these alarms will go off for a particular application. Under normal system operation, it will not dispatch these alarms more than about every minute (at which point every such pending alarm is dispatched); when in low-power idle modes this duration may be significantly longer, such as 15 minutes.

Unlike other alarms, the system is free to reschedule this type of alarm to happen out of order with any other alarms, even those from the same app. This will clearly happen when the device is idle (since this alarm can go off while idle, when any other alarms from the app will be held until later), but may also happen even when not idle. Note that the OS will allow itself more flexibility for scheduling these alarms than regular exact alarms, since the application has opted into this behavior. When the device is idle it may take even more liberties with scheduling in order to optimize for battery life.

Note: Starting with Build.VERSION_CODES#S, apps targeting SDK level 31 or higher need to request the SCHEDULE_EXACT_ALARM permission to use this API, unless the app is exempt from battery restrictions. The user and the system can revoke this permission via the special app access screen in Settings.

Note: Exact alarms should only be used for user-facing features. For more details, see Exact alarm permission.

Alarms scheduled via this API will be allowed to start a foreground service even if the app is in the background.

Parameters
type	int: type of alarm. Value is RTC_WAKEUP, RTC, ELAPSED_REALTIME_WAKEUP, or ELAPSED_REALTIME
triggerAtMillis	long: time in milliseconds that the alarm should go off, using the appropriate clock (depending on the alarm type).
operation	PendingIntent: Action to perform when the alarm goes off; typically comes from IntentSender.getBroadcast(). This value cannot be null.

See also:

• set(int, long, PendingIntent)
• setRepeating(int, long, long, PendingIntent)
• setWindow(int, long, long, PendingIntent)
• cancel(OnAlarmListener)
• Context.sendBroadcast(Intent)
• Context.registerReceiver(BroadcastReceiver, IntentFilter)
• Intent.filterEquals(Intent)
• ELAPSED_REALTIME
• ELAPSED_REALTIME_WAKEUP
• RTC
• RTC_WAKEUP
• SCHEDULE_EXACT_ALARM

setInexactRepeating

Added in API level 3

public void setInexactRepeating (int type, 
                long triggerAtMillis, 
                long intervalMillis, 
                PendingIntent operation)

Schedule a repeating alarm that has inexact trigger time requirements; for example, an alarm that repeats every hour, but not necessarily at the top of every hour. These alarms are more power-efficient than the strict recurrences traditionally supplied by setRepeating(int, long, long, PendingIntent), since the system can adjust alarms' delivery times to cause them to fire simultaneously, avoiding waking the device from sleep more than necessary.

Your alarm's first trigger will not be before the requested time, but it might not occur for almost a full interval after that time. In addition, while the overall period of the repeating alarm will be as requested, the time between any two successive firings of the alarm may vary. If your application demands very low jitter, use one-shot alarms with an appropriate window instead; see setWindow(int, long, long, android.app.PendingIntent) and setExact(int, long, android.app.PendingIntent).

As of API 19, all repeating alarms are inexact. Because this method has been available since API 3, your application can safely call it and be assured that it will get similar behavior on both current and older versions of Android.

Apps targeting Build.VERSION_CODES#S will need to set the flag PendingIntent#FLAG_MUTABLE on the PendingIntent being used to set this alarm, if they want the alarm count to be supplied with the key Intent#EXTRA_ALARM_COUNT.

Parameters
type	int: type of alarm. Value is RTC_WAKEUP, RTC, ELAPSED_REALTIME_WAKEUP, or ELAPSED_REALTIME
triggerAtMillis	long: time in milliseconds that the alarm should first go off, using the appropriate clock (depending on the alarm type). This is inexact: the alarm will not fire before this time, but there may be a delay of almost an entire alarm interval before the first invocation of the alarm.
intervalMillis	long: interval in milliseconds between subsequent repeats of the alarm. Prior to API 19, if this is one of INTERVAL_FIFTEEN_MINUTES, INTERVAL_HALF_HOUR, INTERVAL_HOUR, INTERVAL_HALF_DAY, or INTERVAL_DAY then the alarm will be phase-aligned with other alarms to reduce the number of wakeups. Otherwise, the alarm will be set as though the application had called setRepeating(int, long, long, PendingIntent). As of API 19, all repeating alarms will be inexact and subject to batching with other alarms regardless of their stated repeat interval.
operation	PendingIntent: Action to perform when the alarm goes off; typically comes from IntentSender.getBroadcast(). This value cannot be null.

See also:

• Handler
• set(int, long, PendingIntent)
• cancel(OnAlarmListener)
• Context.sendBroadcast(Intent)
• Context.registerReceiver(BroadcastReceiver, IntentFilter)
• Intent.filterEquals(Intent)
• ELAPSED_REALTIME
• ELAPSED_REALTIME_WAKEUP
• RTC
• RTC_WAKEUP
• INTERVAL_FIFTEEN_MINUTES
• INTERVAL_HALF_HOUR
• INTERVAL_HOUR
• INTERVAL_HALF_DAY
• INTERVAL_DAY
• Intent.EXTRA_ALARM_COUNT

setRepeating

Added in API level 1

public void setRepeating (int type, 
                long triggerAtMillis, 
                long intervalMillis, 
                PendingIntent operation)

Schedule a repeating alarm. Note: for timing operations (ticks, timeouts, etc) it is easier and much more efficient to use Handler. If there is already an alarm scheduled for the same IntentSender, it will first be canceled.

Like set(int, long, PendingIntent), except you can also supply a period at which the alarm will automatically repeat. This alarm continues repeating until explicitly removed with cancel(OnAlarmListener). If the stated trigger time is in the past, the alarm will be triggered immediately, with an alarm count depending on how far in the past the trigger time is relative to the repeat interval.

If an alarm is delayed (by system sleep, for example, for non _WAKEUP alarm types), a skipped repeat will be delivered as soon as possible. After that, future alarms will be delivered according to the original schedule; they do not drift over time. For example, if you have set a recurring alarm for the top of every hour but the phone was asleep from 7:45 until 8:45, an alarm will be sent as soon as the phone awakens, then the next alarm will be sent at 9:00.

If your application wants to allow the delivery times to drift in order to guarantee that at least a certain time interval always elapses between alarms, then the approach to take is to use one-time alarms, scheduling the next one yourself when handling each alarm delivery.

Note: as of API 19, all repeating alarms are inexact. If your application needs precise delivery times then it must use one-time exact alarms, rescheduling each time as described above. Legacy applications whose targetSdkVersion is earlier than API 19 will continue to have all of their alarms, including repeating alarms, treated as exact.

Apps targeting Build.VERSION_CODES#S will need to set the flag PendingIntent#FLAG_MUTABLE on the PendingIntent being used to set this alarm, if they want the alarm count to be supplied with the key Intent#EXTRA_ALARM_COUNT.

Parameters
type	int: type of alarm. Value is RTC_WAKEUP, RTC, ELAPSED_REALTIME_WAKEUP, or ELAPSED_REALTIME
triggerAtMillis	long: time in milliseconds that the alarm should first go off, using the appropriate clock (depending on the alarm type).
intervalMillis	long: interval in milliseconds between subsequent repeats of the alarm.
operation	PendingIntent: Action to perform when the alarm goes off; typically comes from IntentSender.getBroadcast(). This value cannot be null.

See also:

• Handler
• set(int, long, PendingIntent)
• setExact(int, long, PendingIntent)
• setWindow(int, long, long, PendingIntent)
• cancel(OnAlarmListener)
• Context.sendBroadcast(Intent)
• Context.registerReceiver(BroadcastReceiver, IntentFilter)
• Intent.filterEquals(Intent)
• ELAPSED_REALTIME
• ELAPSED_REALTIME_WAKEUP
• RTC
• RTC_WAKEUP
• Intent.EXTRA_ALARM_COUNT

setTime

Added in API level 8

public void setTime (long millis)

Set the system wall clock time. Requires the permission android.permission.SET_TIME.
Requires Manifest.permission.SET_TIME

Parameters
millis	long: time in milliseconds since the Epoch

setTimeZone

Added in API level 1

public void setTimeZone (String timeZone)

Sets the system's persistent default time zone. This is the time zone for all apps, even after a reboot. Use TimeZone.setDefault(TimeZone) if you just want to change the time zone within your app, and even then prefer to pass an explicit TimeZone to APIs that require it rather than changing the time zone for all threads.

On android M and above, it is an error to pass in a non-Olson timezone to this function. Note that this is a bad idea on all Android releases because POSIX and the TimeZone class have opposite interpretations of '+' and '-' in the same non-Olson ID.
Requires Manifest.permission.SET_TIME_ZONE

Parameters
timeZone	String: one of the Olson ids from the list returned by TimeZone.getAvailableIDs()

setWindow

Added in API level 19

public void setWindow (int type, 
                long windowStartMillis, 
                long windowLengthMillis, 
                PendingIntent operation)

Schedule an alarm to be delivered within a given window of time. This method is similar to set(int, long, android.app.PendingIntent), but allows the application to precisely control the degree to which its delivery might be adjusted by the OS. This method allows an application to take advantage of the battery optimizations that arise from delivery batching even when it has modest timeliness requirements for its alarms.

Note: Starting with API Build.VERSION_CODES#S, apps should not pass in a window of less than 10 minutes. The system will try its best to accommodate smaller windows if the alarm is supposed to fire in the near future, but there are no guarantees and the app should expect any window smaller than 10 minutes to get elongated to 10 minutes.

This method can also be used to achieve strict ordering guarantees among multiple alarms by ensuring that the windows requested for each alarm do not intersect.

When precise delivery is not required, applications should use the standard set(int, long, android.app.PendingIntent) method. This will give the OS the most flexibility to minimize wakeups and battery use. For alarms that must be delivered at precisely-specified times with no acceptable variation, applications can use setExact(int, long, android.app.PendingIntent).

Parameters
type	int: type of alarm. Value is RTC_WAKEUP, RTC, ELAPSED_REALTIME_WAKEUP, or ELAPSED_REALTIME
windowStartMillis	long: The earliest time, in milliseconds, that the alarm should be delivered, expressed in the appropriate clock's units (depending on the alarm type).
windowLengthMillis	long: The length of the requested delivery window, in milliseconds. The alarm will be delivered no later than this many milliseconds after windowStartMillis. Note that this parameter is a duration, not the timestamp of the end of the window.
operation	PendingIntent: Action to perform when the alarm goes off; typically comes from IntentSender.getBroadcast(). This value cannot be null.

See also:

• set(int, long, PendingIntent)
• setExact(int, long, PendingIntent)
• setRepeating(int, long, long, PendingIntent)
• cancel(OnAlarmListener)
• Context.sendBroadcast(Intent)
• Context.registerReceiver(BroadcastReceiver, IntentFilter)
• Intent.filterEquals(Intent)
• ELAPSED_REALTIME
• ELAPSED_REALTIME_WAKEUP
• RTC
• RTC_WAKEUP

setWindow

Added in API level 24

public void setWindow (int type, 
                long windowStartMillis, 
                long windowLengthMillis, 
                String tag, 
                AlarmManager.OnAlarmListener listener, 
                Handler targetHandler)

Direct callback version of setWindow(int, long, long, android.app.PendingIntent). Rather than supplying a PendingIntent to be sent when the alarm time is reached, this variant supplies an OnAlarmListener instance that will be invoked at that time.

The OnAlarmListener onAlarm() method will be invoked via the specified target Handler, or on the application's main looper if null is passed as the targetHandler parameter.

Note: Starting with API Build.VERSION_CODES#S, apps should not pass in a window of less than 10 minutes. The system will try its best to accommodate smaller windows if the alarm is supposed to fire in the near future, but there are no guarantees and the app should expect any window smaller than 10 minutes to get elongated to 10 minutes.

Parameters
type	int: Value is RTC_WAKEUP, RTC, ELAPSED_REALTIME_WAKEUP, or ELAPSED_REALTIME
windowStartMillis	long
windowLengthMillis	long
tag	String: This value may be null.
listener	AlarmManager.OnAlarmListener: This value cannot be null.
targetHandler	Handler: This value may be null.

See also:

• setWindow(int, long, long, PendingIntent)

setWindow

Added in API level 34

public void setWindow (int type, 
                long windowStartMillis, 
                long windowLengthMillis, 
                String tag, 
                Executor executor, 
                AlarmManager.OnAlarmListener listener)

Direct callback version of setWindow(int, long, long, android.app.PendingIntent). Rather than supplying a PendingIntent to be sent when the alarm time is reached, this variant supplies an OnAlarmListener instance that will be invoked at that time.

The OnAlarmListener onAlarm() method will be invoked via the specified target Executor.

Note: Starting with API Build.VERSION_CODES#S, apps should not pass in a window of less than 10 minutes. The system will try its best to accommodate smaller windows if the alarm is supposed to fire in the near future, but there are no guarantees and the app should expect any window smaller than 10 minutes to get elongated to 10 minutes.

Parameters
type	int: Value is RTC_WAKEUP, RTC, ELAPSED_REALTIME_WAKEUP, or ELAPSED_REALTIME
windowStartMillis	long
windowLengthMillis	long
tag	String: This value may be null.
executor	Executor: This value cannot be null.
listener	AlarmManager.OnAlarmListener: This value cannot be null.

See also:

• setWindow(int, long, long, PendingIntent)