title: How to save and retrieve Date in SharedPreferences
body: <p>I need to save a few dates in <code>SharedPreferences</code> in android and retrieve it. I am building reminder app using <code>AlarmManager</code> and I need to save list of future dates. It must be able to retrieve as milliseconds. First I thought to calculate time between today now time and future time and store in shared preference. But that method is not working since I need to use it for <code>AlarmManager</code>. </p>