string.xml

<string name="countDownFormat" >%1$02d:%2$02d</string>
<string name="timeFormat">hh:mm a</string>

TimeFormatting.java

//process current time in milliseconds into "00:00 am" format
Timestamp currentTime = new Timestamp(System.currentTimeMillis());
SimpleDateFormat formatter = new SimpleDateFormat(getString(R.string.timeFormat), Locale.getDefault());
String currentTimeString = formatter.format(currentTime); 

//process a number of minutes into "hh:mm" format
long totalMinutesCount = 123;
long hoursCount = TimeUnit.MINUTES.toHours(totalMinutesCount);
long minutesLessHoursCount =
		totalMinutesCount - TimeUnit.HOURS.toMinutes(hoursCount);
//will produce "02:03"
String hoursAndMinutesCount = getString(R.string.countDownFormat,
		hoursCount,
		minutesLessHoursCount);