diff --git a/app/src/main/java/io/timelimit/android/ui/manage/category/timelimit_rules/edit/EditTimeLimitRuleDialogFragment.kt b/app/src/main/java/io/timelimit/android/ui/manage/category/timelimit_rules/edit/EditTimeLimitRuleDialogFragment.kt
index f82f572..347a67b 100644
--- a/app/src/main/java/io/timelimit/android/ui/manage/category/timelimit_rules/edit/EditTimeLimitRuleDialogFragment.kt
+++ b/app/src/main/java/io/timelimit/android/ui/manage/category/timelimit_rules/edit/EditTimeLimitRuleDialogFragment.kt
@@ -134,7 +134,9 @@ class EditTimeLimitRuleDialogFragment : BottomSheetDialogFragment() {
             view.applyToExtraTime = newRule.applyToExtraTimeUsage
             view.timeSpan.timeInMillis = newRule.maximumTimeInMillis.toLong()
 
-            view.timeSpan.maxDays = Math.max(0, (0..6).map { (newRule.dayMask.toInt() shr it) and 1 }.sum() - 1)
+            val affectedDays = Math.max(0, (0..6).map { (newRule.dayMask.toInt() shr it) and 1 }.sum())
+            view.timeSpan.maxDays = affectedDays - 1
+            view.affectsMultipleDays = affectedDays >= 2
         }
 
         bindRule()
diff --git a/app/src/main/res/layout/fragment_edit_time_limit_rule_dialog.xml b/app/src/main/res/layout/fragment_edit_time_limit_rule_dialog.xml
index d741012..6ef81c4 100644
--- a/app/src/main/res/layout/fragment_edit_time_limit_rule_dialog.xml
+++ b/app/src/main/res/layout/fragment_edit_time_limit_rule_dialog.xml
@@ -30,6 +30,10 @@
             name="handlers"
             type="io.timelimit.android.ui.manage.category.timelimit_rules.edit.Handlers" />
 
+        <variable
+            name="affectsMultipleDays"
+            type="boolean" />
+
         <import type="android.view.View" />
     </data>
 
@@ -75,6 +79,13 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content" />
 
+        <TextView
+            android:visibility="@{affectsMultipleDays ? View.VISIBLE : View.GONE}"
+            android:textAppearance="?android:textAppearanceSmall"
+            android:text="@string/category_time_limit_rules_warning_multiple_days"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content" />
+
         <LinearLayout
             android:orientation="horizontal"
             android:layout_width="match_parent"
diff --git a/app/src/main/res/values-de/strings-category-time-limit-rules.xml b/app/src/main/res/values-de/strings-category-time-limit-rules.xml
index 91e9102..19380f7 100644
--- a/app/src/main/res/values-de/strings-category-time-limit-rules.xml
+++ b/app/src/main/res/values-de/strings-category-time-limit-rules.xml
@@ -31,4 +31,9 @@
     <string name="category_time_limit_rules_snackbar_created">Regel wurde erstellt</string>
     <string name="category_time_limit_rules_snackbar_updated">Regel wurde geändert</string>
     <string name="category_time_limit_rules_snackbar_deleted">Regel wurde gelöscht</string>
+
+    <string name="category_time_limit_rules_warning_multiple_days">Diese Regel
+        wird die Gesamtnutzungsdauer in einer Woche an den gewählten Tagen einschränken.
+        Wenn Sei die Begrenzung je Tag wollen, dann erstellen Sie eine Regel je Tag.
+    </string>
 </resources>
diff --git a/app/src/main/res/values/strings-category-time-limit-rules.xml b/app/src/main/res/values/strings-category-time-limit-rules.xml
index 9eb6166..9413b9b 100644
--- a/app/src/main/res/values/strings-category-time-limit-rules.xml
+++ b/app/src/main/res/values/strings-category-time-limit-rules.xml
@@ -31,4 +31,9 @@
     <string name="category_time_limit_rules_snackbar_created">Rule was created</string>
     <string name="category_time_limit_rules_snackbar_updated">Rule was modified</string>
     <string name="category_time_limit_rules_snackbar_deleted">Rule was deleted</string>
+
+    <string name="category_time_limit_rules_warning_multiple_days">This rule
+        will limit the total usage duration during one week at the selected days.
+        If you want it per day, create one rule per day.
+    </string>
 </resources>