I am building an alarm application. I currently have a ListActivity which display the list of alarms and another activity which changes the time of a particular alarm. My problem is, when I decide to enter into the activity to change the time of an alarm and then I press the back button, it does not refresh. However, I've implemented a button that redirects back to the ListActivity and if I press it, the list of alarms are refreshed. How can I, after pressing the back button, refresh the list of alarms?