diff --git a/Assets/Translations/de.json b/Assets/Translations/de.json
index a3318920..807f4fb4 100644
--- a/Assets/Translations/de.json
+++ b/Assets/Translations/de.json
@@ -631,6 +631,14 @@
         "week-numbers": {
           "label": "Wochennummern anzeigen",
           "description": "Zeigt die Woche des Jahres (z.B. Woche 38) im Kalender an."
+        },
+        "first-day-of-week": {
+          "label": "Erster Tag der Woche",
+          "description": "Wählen Sie, welcher Tag die Kalenderwoche beginnt.",
+          "auto": "Systemstandard",
+          "monday": "Montag",
+          "saturday": "Samstag",
+          "sunday": "Sonntag"
         }
       }
     },
diff --git a/Assets/Translations/en.json b/Assets/Translations/en.json
index cbad3dd8..765201aa 100644
--- a/Assets/Translations/en.json
+++ b/Assets/Translations/en.json
@@ -631,6 +631,14 @@
         "week-numbers": {
           "label": "Show week numbers",
           "description": "Displays the week of the year (e.g., Week 38) in the calendar."
+        },
+        "first-day-of-week": {
+          "label": "First day of week",
+          "description": "Choose which day starts the calendar week.",
+          "auto": "System default",
+          "monday": "Monday",
+          "saturday": "Saturday",
+          "sunday": "Sunday"
         }
       }
     },
diff --git a/Assets/Translations/es.json b/Assets/Translations/es.json
index 2db6da8f..0a4f77f4 100644
--- a/Assets/Translations/es.json
+++ b/Assets/Translations/es.json
@@ -624,6 +624,14 @@
         "week-numbers": {
           "label": "Mostrar números de semana",
           "description": "Muestra la semana del año (ej., Semana 38) en el calendario."
+        },
+        "first-day-of-week": {
+          "label": "Primer día de la semana",
+          "description": "Elige qué día comienza la semana del calendario.",
+          "auto": "Predeterminado del sistema",
+          "monday": "Lunes",
+          "saturday": "Sábado",
+          "sunday": "Domingo"
         }
       }
     },
diff --git a/Assets/Translations/fr.json b/Assets/Translations/fr.json
index 8131592a..eb401542 100644
--- a/Assets/Translations/fr.json
+++ b/Assets/Translations/fr.json
@@ -624,6 +624,14 @@
         "week-numbers": {
           "label": "Afficher les numéros de semaine",
           "description": "Affiche la semaine de l'année (ex: Semaine 38) dans le calendrier."
+        },
+        "first-day-of-week": {
+          "label": "Premier jour de la semaine",
+          "description": "Choisissez quel jour commence la semaine du calendrier.",
+          "auto": "Par défaut du système",
+          "monday": "Lundi",
+          "saturday": "Samedi",
+          "sunday": "Dimanche"
         }
       }
     },
diff --git a/Assets/Translations/pt.json b/Assets/Translations/pt.json
index dd3fe7f0..cdd14da2 100644
--- a/Assets/Translations/pt.json
+++ b/Assets/Translations/pt.json
@@ -586,6 +586,14 @@
         "week-numbers": {
           "label": "Mostrar números da semana",
           "description": "Exibe a semana do ano (ex., Semana 38) no calendário."
+        },
+        "first-day-of-week": {
+          "label": "Primeiro dia da semana",
+          "description": "Escolha qual dia inicia a semana do calendário.",
+          "auto": "Padrão do sistema",
+          "monday": "Segunda-feira",
+          "saturday": "Sábado",
+          "sunday": "Domingo"
         }
       }
     },
diff --git a/Assets/Translations/zh-CN.json b/Assets/Translations/zh-CN.json
index 4738030b..427e7c41 100644
--- a/Assets/Translations/zh-CN.json
+++ b/Assets/Translations/zh-CN.json
@@ -624,6 +624,14 @@
         "week-numbers": {
           "label": "显示周数",
           "description": "在日历中显示一年中的第几周（例如：第 38 周）。"
+        },
+        "first-day-of-week": {
+          "label": "每周第一天",
+          "description": "选择日历每周的起始日。",
+          "auto": "系统默认",
+          "monday": "星期一",
+          "saturday": "星期六",
+          "sunday": "星期日"
         }
       }
     },
diff --git a/Assets/settings-default.json b/Assets/settings-default.json
index 57033237..6e1b77a2 100644
--- a/Assets/settings-default.json
+++ b/Assets/settings-default.json
@@ -74,7 +74,8 @@
     "weatherEnabled": true,
     "useFahrenheit": false,
     "use12hourFormat": false,
-    "showWeekNumberInCalendar": false
+    "showWeekNumberInCalendar": false,
+    "firstDayOfWeek": "auto"
   },
   "screenRecorder": {
     "directory": "",
diff --git a/Commons/I18n.qml b/Commons/I18n.qml
index 4ec5e86f..59eeb922 100644
--- a/Commons/I18n.qml
+++ b/Commons/I18n.qml
@@ -8,7 +8,6 @@ import qs.Commons
 Singleton {
   id: root
 
-
   property bool isLoaded: false
   property string langCode: ""
   property string systemDetectedLangCode: ""
diff --git a/Commons/Settings.qml b/Commons/Settings.qml
index f98e3e3e..236277b1 100644
--- a/Commons/Settings.qml
+++ b/Commons/Settings.qml
@@ -202,6 +202,7 @@ Singleton {
       property bool useFahrenheit: false
       property bool use12hourFormat: false
       property bool showWeekNumberInCalendar: false
+      property string firstDayOfWeek: "auto" // "auto", "monday", "saturday", "sunday"
     }
 
     // screen recorder
diff --git a/Modules/Bar/Calendar/CalendarPanel.qml b/Modules/Bar/Calendar/CalendarPanel.qml
index b882324d..3b8bdd45 100644
--- a/Modules/Bar/Calendar/CalendarPanel.qml
+++ b/Modules/Bar/Calendar/CalendarPanel.qml
@@ -22,7 +22,24 @@ NPanel {
     anchors.margins: Style.marginL
     spacing: Style.marginM
 
-    readonly property int firstDayOfWeek: Qt.locale().firstDayOfWeek
+    readonly property int firstDayOfWeek: {
+      var setting = Settings.data.location.firstDayOfWeek
+      if (!setting)
+        return Qt.Monday
+
+      switch (setting) {
+      case "auto":
+        return Qt.locale().firstDayOfWeek
+      case "monday":
+        return Qt.Monday
+      case "saturday":
+        return 6 // Qt.Saturday
+      case "sunday":
+        return Qt.Sunday
+      default:
+        return Qt.Monday
+      }
+    }
     property bool isCurrentMonth: checkIsCurrentMonth()
     readonly property bool weatherReady: Settings.data.location.weatherEnabled && (LocationService.data.weather !== null)
 
@@ -278,7 +295,7 @@ NPanel {
       }
     }
 
-    // ... (rest of the file is unchanged) ...
+    // Weather forecast
     RowLayout {
       visible: weatherReady
       Layout.fillWidth: true
@@ -446,38 +463,88 @@ NPanel {
           }
         }
       }
-      MonthGrid {
+      GridLayout {
         id: grid
         Layout.fillWidth: true
         Layout.fillHeight: true
-        spacing: Style.marginXXS
-        month: Time.date.getMonth()
-        year: Time.date.getFullYear()
-        locale: Qt.locale()
-        delegate: Item {
-          Rectangle {
-            width: Style.baseWidgetSize * 0.9
-            height: Style.baseWidgetSize * 0.9
-            anchors.centerIn: parent
-            radius: Style.radiusM
-            color: model.today ? Color.mSecondary : Color.transparent
-            NText {
-              anchors.centerIn: parent
-              text: model.day
-              color: {
-                if (model.today)
-                  return Color.mOnSecondary
-                if (model.month === grid.month)
-                  return Color.mOnSurface
-                return Color.mOnSurfaceVariant
-              }
-              opacity: model.month === grid.month ? 1.0 : 0.4
-              pointSize: Style.fontSizeM
-              font.weight: model.today ? Style.fontWeightBold : Style.fontWeightMedium
+        columns: 7
+        rowSpacing: Style.marginXXS
+        columnSpacing: Style.marginXXS
+
+        property int month: Time.date.getMonth()
+        property int year: Time.date.getFullYear()
+
+        Repeater {
+          model: 42 // 6 rows × 7 days
+          delegate: Item {
+            id: cellItem
+            Layout.fillWidth: true
+            Layout.fillHeight: true
+
+            required property int index
+
+            property int cellDay: {
+              let firstOfMonth = new Date(grid.year, grid.month, 1)
+              let firstDayOfWeek = content.firstDayOfWeek
+              let firstOfMonthDayOfWeek = firstOfMonth.getDay()
+              let daysBeforeFirst = (firstOfMonthDayOfWeek - firstDayOfWeek + 7) % 7
+              let startDate = new Date(grid.year, grid.month, 1 - daysBeforeFirst)
+              let currentDate = new Date(startDate)
+              currentDate.setDate(startDate.getDate() + cellItem.index)
+              return currentDate.getDate()
             }
-            Behavior on color {
-              ColorAnimation {
-                duration: Style.animationFast
+
+            property int cellMonth: {
+              let firstOfMonth = new Date(grid.year, grid.month, 1)
+              let firstDayOfWeek = content.firstDayOfWeek
+              let firstOfMonthDayOfWeek = firstOfMonth.getDay()
+              let daysBeforeFirst = (firstOfMonthDayOfWeek - firstDayOfWeek + 7) % 7
+              let startDate = new Date(grid.year, grid.month, 1 - daysBeforeFirst)
+              let currentDate = new Date(startDate)
+              currentDate.setDate(startDate.getDate() + cellItem.index)
+              return currentDate.getMonth()
+            }
+
+            property int cellYear: {
+              let firstOfMonth = new Date(grid.year, grid.month, 1)
+              let firstDayOfWeek = content.firstDayOfWeek
+              let firstOfMonthDayOfWeek = firstOfMonth.getDay()
+              let daysBeforeFirst = (firstOfMonthDayOfWeek - firstDayOfWeek + 7) % 7
+              let startDate = new Date(grid.year, grid.month, 1 - daysBeforeFirst)
+              let currentDate = new Date(startDate)
+              currentDate.setDate(startDate.getDate() + cellItem.index)
+              return currentDate.getFullYear()
+            }
+
+            property bool isToday: cellDay === Time.date.getDate() && cellMonth === Time.date.getMonth() && cellYear === Time.date.getFullYear()
+            property bool isCurrentMonth: cellMonth === grid.month
+
+            Rectangle {
+              width: Style.baseWidgetSize * 0.9
+              height: Style.baseWidgetSize * 0.9
+              anchors.centerIn: parent
+              radius: Style.radiusM
+              color: parent.isToday ? Color.mSecondary : Color.transparent
+
+              NText {
+                anchors.centerIn: parent
+                text: cellItem.cellDay
+                color: {
+                  if (cellItem.isToday)
+                    return Color.mOnSecondary
+                  if (cellItem.isCurrentMonth)
+                    return Color.mOnSurface
+                  return Color.mOnSurfaceVariant
+                }
+                opacity: cellItem.isCurrentMonth ? 1.0 : 0.5
+                pointSize: Style.fontSizeM
+                font.weight: cellItem.isToday ? Style.fontWeightBold : Style.fontWeightSemiBold
+              }
+
+              Behavior on color {
+                ColorAnimation {
+                  duration: Style.animationFast
+                }
               }
             }
           }
diff --git a/Modules/Settings/Tabs/GeneralTab.qml b/Modules/Settings/Tabs/GeneralTab.qml
index 40b5276d..4f084445 100644
--- a/Modules/Settings/Tabs/GeneralTab.qml
+++ b/Modules/Settings/Tabs/GeneralTab.qml
@@ -204,20 +204,24 @@ ColumnLayout {
       Layout.fillWidth: true
       label: I18n.tr("settings.general.language.select.label")
       description: I18n.tr("settings.general.language.select.description")
-      model: [
-        { "key": "", "name": I18n.tr("settings.general.language.select.auto-detect") + " (" + I18n.systemDetectedLangCode + ")" }
-      ].concat(I18n.availableLanguages.map(function(langCode) {
-        return { "key": langCode, "name": langCode }
-      }))
+      model: [{
+          "key": "",
+          "name": I18n.tr("settings.general.language.select.auto-detect") + " (" + I18n.systemDetectedLangCode + ")"
+        }].concat(I18n.availableLanguages.map(function (langCode) {
+          return {
+            "key": langCode,
+            "name": langCode
+          }
+        }))
       currentKey: Settings.data.general.language
       onSelected: key => {
-        Settings.data.general.language = key
-        if (key === "") {
-          I18n.detectLanguage() // Re-detect system language if "Automatic" is selected
-        } else {
-          I18n.setLanguage(key) // Set specific language
-        }
-      }
+                    Settings.data.general.language = key
+                    if (key === "") {
+                      I18n.detectLanguage() // Re-detect system language if "Automatic" is selected
+                    } else {
+                      I18n.setLanguage(key) // Set specific language
+                    }
+                  }
     }
   }
 
diff --git a/Modules/Settings/Tabs/LocationTab.qml b/Modules/Settings/Tabs/LocationTab.qml
index 7b6c340b..0fb7f8a2 100644
--- a/Modules/Settings/Tabs/LocationTab.qml
+++ b/Modules/Settings/Tabs/LocationTab.qml
@@ -117,6 +117,27 @@ ColumnLayout {
       checked: Settings.data.location.showWeekNumberInCalendar
       onToggled: checked => Settings.data.location.showWeekNumberInCalendar = checked
     }
+
+    NComboBox {
+      label: I18n.tr("settings.location.date-time.first-day-of-week.label")
+      description: I18n.tr("settings.location.date-time.first-day-of-week.description")
+      minimumWidth: 220 * Style.uiScaleRatio
+      model: [{
+          "key": "auto",
+          "name": I18n.tr("settings.location.date-time.first-day-of-week.auto")
+        }, {
+          "key": "monday",
+          "name": I18n.tr("settings.location.date-time.first-day-of-week.monday")
+        }, {
+          "key": "saturday",
+          "name": I18n.tr("settings.location.date-time.first-day-of-week.saturday")
+        }, {
+          "key": "sunday",
+          "name": I18n.tr("settings.location.date-time.first-day-of-week.sunday")
+        }]
+      currentKey: Settings.data.location.firstDayOfWeek
+      onSelected: key => Settings.data.location.firstDayOfWeek = key
+    }
   }
 
   NDivider {