title: Give notifications on specific time
body: <p>I created an app in which user can add events in calendar and I want to give user reminder about their event at specific time. Date and time is already specified in event. I want to set notifications for each event.
  I searched about it on google and found about alarm Manager but I am confused on how milli second parameter works. Like I want set alarm for 7:30 PM but don't know how it can be done.</p>