Develop Reference

AlarmsManager triggers whenever it wants

I want to trigger a notification each day at a specific time choosen by the user, like 6' / 7' / 8'.
For this, I created a WakefulBroadcastReceiver, that pass to an IntentService to create the notification.
And this is how I setup my AlarmsManager. timeInHours is an integer passed as parameter, between 6 and 12 :
Intent i = new Intent(context, StepCountNotifyBroadcast.class);
PendingIntent pi = PendingIntent.getBroadcast(context, 0, i, 0);
// Get the next day at timeInHours hours'.
Calendar cal = Calendar.getInstance();
cal.setTime(new Date()); // compute start of the day for the timestamp
cal.set(Calendar.HOUR_OF_DAY, timeInHours);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
cal.set(Calendar.AM_PM, Calendar.AM);
if (new Date().getTime() > cal.getTime().getTime())
cal.add(Calendar.DAY_OF_YEAR, 1);
long nextDay = cal.getTime().getTime();
// Setup the alarm.
long timeBetween = AlarmManager.INTERVAL_DAY; // Each day.
AlarmManager alarms = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarms.cancel(pi);
alarms.setRepeating(AlarmManager.RTC_WAKEUP, nextDay, timeBetween, pi);
Date nextDayAsDate = new Date(nextDay);
GLog.d("AlarmUtils", "scheduleNotifiation for next date: " + nextDayAsDate.toString());
It works well 50% of the time, but still do crazy things like... Trigger the notification at 2:00 AM ?!
I know the system will not trigger the notification at the specific time I want and this is ok. But here we talk about approximately 18 hours later.
In logs, it seems that my IntentService code is effectively running in the middle of the night in some cases. So that's not an issue with the notification itself.
I can switch this line :
alarms.setRepeating(AlarmManager.RTC_WAKEUP, nextDay, timeBetween, pi);
to another line of code :
alarms.setExact(AlarmManager.RTC_WAKEUP, nextDay, pi);
But this is not good for the battery life I'm afraid.
Now my questions :
Can somebody tell me a reason about the way Android devices works with AlarmsManager ?
Do you find another solution than will not drain battery life and be sure the notification will be triggered in maximum 2 or 3 hours later?
Do you have any ideas, in this particular case, to debug and do code testing without waiting a day or two to detect issues?
Thanks in advance.

After API Level 23, Doze mode was introduced on the Android System to reduce battery consumption. Go through below link:
How to make Alarm Manager work when Android 6.0 in Doze mode?

Android - Alarm manager runs every day

I don't understand what's wrong but my alarm runs every single day even if I hardcode the day number, I have no idea whats going on...
Intent notificationIntent = new Intent(AddTask.this,CustomBroadcastReceiver.class);
notificationIntent.putExtra(Intent.EXTRA_UID,newTaskId);
PendingIntent pendingIntent = PendingIntent.getBroadcast(AddTask.this, newTaskId, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager alarmManager = (AlarmManager)getSystemService(getApplicationContext().ALARM_SERVICE);
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.HOUR_OF_DAY, hour);
calendar.set(Calendar.MINUTE, minute);
calendar.set(Calendar.DAY_OF_WEEK,2);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),AlarmManager.INTERVAL_DAY * 7, pendingIntent);
today is sunday so the day number is 1 and i wrote calendar.set(Calendar.DAY_OF_WEEK,2); and the alarm just got trigered since i used the time and minute of this moment... it doesnot matter if i set the day number 1 2 3 4 5 or 6 or even if i make several alarm managers with same ID and each contains other day it triggers every day

Why is this line necessary?
calendar.setTimeInMillis(System.currentTimeMillis());
Also, the android development documentation recommends using
setInexactRepeating(int type, long triggerAtMillis, long intervalMillis, PendingIntent operation);
EDIT:
I suspect the intent isn't set for creating alarms so it's not creating the alarms correctly.
Maybe this would work:
Intent intent = new Intent(this, AlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0,
intent, PendingIntent.FLAG_ONE_SHOT);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
//set repeating alarm here
I hope that answers the question.

So okay i have solved this , for everyone who want to create an alarm application like this > you set the time and hour and the days of week to trigger the alarm, it works like this : if today is the day which you choosed you just set the alarm with this :
calendar.set(Calendar.HOUR_OF_DAY, hour);
calendar.set(Calendar.MINUTE, minute);
but IF the day you picked is not the day which is today you have to the the date of the nearest day you picked and then just set the additional hour and minute as above.
this is the only way to make it work

Notification shows not in exact time

I know that this topic is explained fairly well and there are a lot of tutorials. But maybe I'm too new in android to understand what I'm doing wrong.
I need to implement support of set of reminders. And notification should be shown exactly every Monday at 15 pm. I checked a lot of tutorials and similar questions on this site but anyway notification shows, somehow, randomly.
How do I test implementation:
Current time is 14:55
I set reminder on Monday at 15:00
And right after SAVE notification is shown.
Because of (just for example) I set repeat period in 20 sec, this notification is shown again and again with delay of 20 sec. But current time is still between 14:55 and 15:00.
And my task is to run notification at 15:00 or a liitle later. But not before.
set repeating notification
AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, NotifyService.class);
PendingIntent pendingIntent = PendingIntent.getService(context, (int) reminder.id, intent, 0);
final Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.DAY_OF_WEEK, 2);
calendar.set(Calendar.HOUR_OF_DAY, reminder.time.hour);
calendar.set(Calendar.MINUTE, reminder.time.minute);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
am.setRepeating(AlarmManager.RTC_WAKEUP,
Calendar.getInstance().getTimeInMillis(), 20000, pendingIntent);
BTW
my min SDK version is 7, so I cannot use methods like setExact()
android version on tested device is 4.4.2
Thanks

When you set the alarm you set it with Calendar.getInstance().getTimeInMillis() instead of calendar.getTimeInMillis(). Simple bug ;).
Basically setting the alarm to 'now' every time, ignoring your calendar object.

android-can't run a code one a day

This is a code that i'm using for running a service once a day .
the problem is this , after 24h , the service keeps calling every 10 to 15 min .
Intent myIntent = new Intent(this, MyService.class);
pendingIntent = PendingIntent.getService(this, 0, myIntent, 0);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.add(Calendar.HOUR, 24);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,calendar.getTimeInMillis(), 86400, pendingIntent);
I think I'm using a bad code .Could you give me a better code for runnig a service once or twice a day
thanks you

The interval parameter to setRepeating represents millis. It should be 86400000 to get it right.
You are now programming an alarm to start first execution 24h past the current time, but with a period of 86400 millis (less than two minutes).
Morale of the story:
Always read the docs before using an API.
Use AlarmManager.INTERVAL_DAY instead of your own magic numbers

set irregular alarms daily using alarmManager

I want to set notifications/alarms everyday at specific times. Please note that these times could be different for everyday. For example I have a Database from which I get 5 different entries/times for a day e.g 6am, 1.30pm, 4.30pm, 7.30pm, 10.00 pm. I want to set an alarm for these times. For the next day these times could be different. They could be off by 2-5 minutes or more.
Basically I cannot set a recurring alarm for the same time everyday. I need to check the entry in my Database to know what time I should schedule it.
What is a good and efficient way of doing this. I looked at some stack overflow questions for setting multiple alarms. But here how do I do it? Should I just read the whole weeks database entries i.e 5 times/day for 7 days..And set around 35 alarms together? Or should I just set one alarm at a time. And when that alarm is fired just read the next entry from the Database and schedule an alarm for that time?

Write a service which will pick up the 5 values from the database everyday at a particular time.
Then add multiple entries in the AlarmManger with different unique ID.
Adding alarm at particular time:
Calendar calendar = Calendar.getInstance();
//9 AM
calendar.set(Calendar.HOUR_OF_DAY, 9);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
PendingIntent pi = PendingIntent.getService(context, 0, new Intent(context, YourClass.class), PendingIntent.FLAG_UPDATE_CURRENT);
am.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), AlarmManager.INTERVAL_DAY, pi);
Setting Multiple alarm:
AlarmManager[] alarmManager=new AlarmManager[24];
intentArray = new ArrayList<PendingIntent>();
for(f=0;f<arr2.length;f++){
Intent intent = new Intent(AlarmR.this, Riciving.class);
pi=PendingIntent.getBroadcast(AlarmR.this, f,intent, 0);
alarmManager[f] = (AlarmManager) getSystemService(ALARM_SERVICE);
alarmManager[f].set(AlarmManager.RTC_WAKEUP,arr2[f] ,pi);
intentArray.add(pi);
}
Hope this should work.