Fixes timezone bug and arithmetic overflow

src/org/isoron/uhabits/dialogs/ShowHabitsFragment.java

@@ -231,8 +231,8 @@ public class ShowHabitsFragment extends Fragment implements OnSavedListener, OnI
 		listView.setOnTouchListener(controller);
 		listView.setDragEnabled(true);
 
-		GregorianCalendar day = new GregorianCalendar();
-		day.setTimeInMillis(DateHelper.getLocalTime());
+		GregorianCalendar day = new GregorianCalendar(TimeZone.getTimeZone("GMT"));
+		day.setTimeInMillis(DateHelper.getStartOfDay(DateHelper.getLocalTime()));
 		
 		for (int i = 0; i < button_count; i++)
 		{

src/org/isoron/uhabits/models/Habit.java

@@ -9,6 +9,7 @@ import org.isoron.uhabits.R;
 
 import android.annotation.SuppressLint;
 import android.graphics.Color;
+import android.util.Log;
 
 import com.activeandroid.Model;
 import com.activeandroid.annotation.Column;
@@ -258,7 +259,7 @@ public class Habit extends Model
 
 	public int[] getReps(long timeFrom, long timeTo)
 	{
-		long timeFromExtended = timeFrom - freq_den * DateHelper.millisecondsInOneDay;
+		long timeFromExtended = timeFrom - (long)(freq_den) * DateHelper.millisecondsInOneDay;
 		List<Repetition> reps = selectRepsFromTo(timeFromExtended, timeTo).execute();
 
 		int nDaysExtended = (int) ((timeTo - timeFromExtended) / DateHelper.millisecondsInOneDay);