Question

for example i want to have an alarm that will fire every sunday at noon…. how would i do this?

Answer 1

Use the AlarmManager class:

http://developer.android.com/reference/android/app/AlarmManager.html

Class Overview

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.

Use public void set (int type, long triggerAtTime, PendingIntent operation) to set the time to fire it.

Use void setRepeating(int type, long triggerAtTime, long interval, PendingIntent operation) to schedule a repeating alarm.

Here’s a full example. I don’t really remember all the Calendar methods, so I’m sure that part can be streamlined, but this is a start and you can optimize it later:

AlarmManager alarm = (AlarmMAnager) Context.getSystemService(Context.ALARM_SERVICE);
Calendar timeOff = Calendar.getInstance();
int days = Calendar.SUNDAY + (7 - timeOff.get(Calendar.DAY_OF_WEEK)); // how many days until Sunday
timeOff.add(Calendar.DATE, days);
timeOff.set(Calendar.HOUR, 12);
timeOff.set(Calendar.MINUTE, 0);
timeOff.set(Calendar.SECOND, 0);

alarm.set(AlarmManager.RTC_WAKEUP, timeOff.getTimeInMillis(), yourOperation);