why my code is so slow?

why my code is so slow?

i runing this code on android after load a cursor with the query i pass to
the adapter, but my date is in long in milliseconds format so a need to
format properly before load the adapter! problem is this code is taking 14
seconds to pass a 50 items load, the problem get worst if i call it inside
the adapter getView cause get slow when i scrool, if i take this function
out the program runs smoothly
this is call inside my listfragment
private String dateFormatPatternEdited(long timeMS) {
android.text.format.DateFormat df = new android.text.format.DateFormat();
final Calendar eDate = Calendar.getInstance();
Calendar sDate = Calendar.getInstance();
sDate.setTimeInMillis(timeMS);
long daysBetween = 0;
while (sDate.before(eDate)) {
sDate.add(Calendar.DAY_OF_MONTH, 1);
daysBetween++;
}
String mDateFormatPattern =
FuelTrackerApplication.dateFormat.format(timeMS);
if (daysBetween < 2){
mDateFormatPattern =
FuelTrackerApplication.timeFormat.format(timeMS);
} else if(daysBetween < 365){
mDateFormatPattern =
df.format(FuelTrackerApplication.dateFormatPattern,timeMS).toString();
}
return mDateFormatPattern;
}
and this is were i initialize the date formats i gonna use its called
inside onCreate in FuelTrackerApplication i dont think theres nothing
wrong with this
public void initializeDateFormat() {
android.text.format.DateFormat df = new android.text.format.DateFormat();
dateFormatPattern = "MMM dd";
if (android.os.Build.VERSION.SDK_INT >= 18){
dateFormatPattern = df.getBestDateTimePattern(Locale.getDefault(),
dateFormatPattern);
}
dateFormat = df.getMediumDateFormat(getApplicationContext());
timeFormat = df.getTimeFormat(getApplicationContext());
dateFormat2 = df.getLongDateFormat(getApplicationContext());
}