diff --git a/app/src/main/java/org/isoron/uhabits/helpers/DateHelper.java b/app/src/main/java/org/isoron/uhabits/helpers/DateHelper.java
index b92623676..d092a406a 100644
--- a/app/src/main/java/org/isoron/uhabits/helpers/DateHelper.java
+++ b/app/src/main/java/org/isoron/uhabits/helpers/DateHelper.java
@@ -183,12 +183,17 @@ public class DateHelper
      *
      * So we have {@code wdaysIndex = dayNumber % 7}
      *
-     * @return array with names from Saturday to Friday according to the current locale
+     * @return weekday number in the internal interpretation
      *
      * @see #getWeekday(long)
      * @see java.util.Calendar#SUNDAY
      *
      */
+    public static int weekDayNumber2wdays(int number)
+    {
+        return number % 7;
+    }
+
     public static String[] getDayNames(int format)
     {
         String[] wdays = new String[7];
diff --git a/app/src/main/java/org/isoron/uhabits/views/HabitFrequencyView.java b/app/src/main/java/org/isoron/uhabits/views/HabitFrequencyView.java
index 1f1f712e5..2d7750483 100644
--- a/app/src/main/java/org/isoron/uhabits/views/HabitFrequencyView.java
+++ b/app/src/main/java/org/isoron/uhabits/views/HabitFrequencyView.java
@@ -65,7 +65,6 @@ public class HabitFrequencyView extends ScrollableDataView implements HabitDataV
     private HashMap<Long, Integer[]> frequency;
     private String wdays[];
     private Integer[] localeWeekdayList;
-    private Map<Integer, Integer> number2wdays;
 
     public HabitFrequencyView(Context context)
     {
@@ -94,12 +93,7 @@ public class HabitFrequencyView extends ScrollableDataView implements HabitDataV
 
         wdays = DateHelper.getShortDayNames();
 
-        /**
-         * here we create the mapping of week days numbers into the "wdays"-indices
-         * @see DateHelper#getDayNames(int)
-         */
         localeWeekdayList = DateHelper.getLocaleWeekdayList();
-        number2wdays = DateHelper.getWeekdayMap();
 
         dfMonth = DateHelper.getDateFormat("MMM");
         dfYear = DateHelper.getDateFormat("yyyy");
@@ -245,7 +239,7 @@ public class HabitFrequencyView extends ScrollableDataView implements HabitDataV
             rect.set(0, 0, baseSize, baseSize);
             rect.offset(prevRect.left, prevRect.top + columnWidth * j);
 
-            int i = number2wdays.get(localeWeekdayList[j]);
+            int i = DateHelper.weekDayNumber2wdays(localeWeekdayList[j]);
             if(values != null)
                 drawMarker(canvas, rect, values[i]);
 
@@ -284,7 +278,7 @@ public class HabitFrequencyView extends ScrollableDataView implements HabitDataV
         pGrid.setColor(dimmedTextColor);
 
         for (Integer dayNumber : localeWeekdayList) {
-            canvas.drawText(wdays[number2wdays.get(dayNumber)], rGrid.right - columnWidth,
+            canvas.drawText(wdays[DateHelper.weekDayNumber2wdays(dayNumber)], rGrid.right - columnWidth,
                     rGrid.top + rowHeight / 2 + 0.25f * em, pText);
 
             pGrid.setStrokeWidth(1f);
diff --git a/app/src/main/java/org/isoron/uhabits/views/HabitHistoryView.java b/app/src/main/java/org/isoron/uhabits/views/HabitHistoryView.java
index 66f84d61f..7a5642d97 100644
--- a/app/src/main/java/org/isoron/uhabits/views/HabitHistoryView.java
+++ b/app/src/main/java/org/isoron/uhabits/views/HabitHistoryView.java
@@ -59,8 +59,6 @@ public class HabitHistoryView extends ScrollableDataView implements HabitDataVie
     private int nColumns;
 
     private String wdays[];
-    private Integer[] localeWeekdayList;
-    private Map<Integer, Integer> number2wdays;
     private SimpleDateFormat dfMonth;
     private SimpleDateFormat dfYear;
 
@@ -106,9 +104,6 @@ public class HabitHistoryView extends ScrollableDataView implements HabitDataVie
         dfMonth = DateHelper.getDateFormat("MMM");
         dfYear = DateHelper.getDateFormat("yyyy");
 
-        localeWeekdayList = DateHelper.getLocaleWeekdayList();
-        number2wdays = DateHelper.getWeekdayMap();
-
         baseLocation = new RectF();
     }
 
@@ -306,10 +301,10 @@ public class HabitHistoryView extends ScrollableDataView implements HabitDataVie
 
     private void drawAxis(Canvas canvas, RectF location)
     {
-        for (Integer dayNumber : localeWeekdayList)
+        for (Integer dayNumber : DateHelper.getLocaleWeekdayList())
         {
             location.offset(0, columnWidth);
-            canvas.drawText(wdays[number2wdays.get(dayNumber)], location.left + headerTextOffset,
+            canvas.drawText(wdays[DateHelper.weekDayNumber2wdays(dayNumber)], location.left + headerTextOffset,
                     location.bottom - headerTextOffset, pTextHeader);
         }
     }