diff --git a/app/src/main/kotlin/org/fossify/clock/activities/MainActivity.kt b/app/src/main/kotlin/org/fossify/clock/activities/MainActivity.kt
index ad5713ed..c3dd4d0f 100644
--- a/app/src/main/kotlin/org/fossify/clock/activities/MainActivity.kt
+++ b/app/src/main/kotlin/org/fossify/clock/activities/MainActivity.kt
@@ -40,6 +40,7 @@ class MainActivity : SimpleActivity() {
         initFragments()
         setupTabs()
         updateWidgets()
+        migrateFirstDayOfWeek()
 
         getEnabledAlarms { enabledAlarms ->
             if (enabledAlarms.isNullOrEmpty()) {
@@ -298,6 +299,16 @@ class MainActivity : SimpleActivity() {
         startAboutActivity(R.string.app_name, licenses, BuildConfig.VERSION_NAME, faqItems, true)
     }
 
+    @Deprecated("Remove this method in future releases")
+    private fun migrateFirstDayOfWeek() {
+        // check existing config.isSundayFirst to migrate setting value
+        if (config.isSundayFirst) {
+            config.firstDayOfWeek = 6
+            // revert old setting to not run this code anymore
+            config.isSundayFirst = false
+        }
+    }
+
     private fun getTabIndex(tabId: Int): Int {
         return when (tabId) {
             TAB_CLOCK -> TAB_CLOCK_INDEX
diff --git a/app/src/main/kotlin/org/fossify/clock/activities/SettingsActivity.kt b/app/src/main/kotlin/org/fossify/clock/activities/SettingsActivity.kt
index d81eb8ec..d1e7ab2b 100644
--- a/app/src/main/kotlin/org/fossify/clock/activities/SettingsActivity.kt
+++ b/app/src/main/kotlin/org/fossify/clock/activities/SettingsActivity.kt
@@ -103,7 +103,7 @@ class SettingsActivity : SimpleActivity() {
         setupLanguage()
         setupDefaultTab()
         setupPreventPhoneFromSleeping()
-        setupSundayFirst()
+        setupStartWeekOn()
         setupAlarmMaxReminder()
         setupUseSameSnooze()
         setupSnoozeTime()
@@ -196,11 +196,24 @@ class SettingsActivity : SimpleActivity() {
         }
     }
 
-    private fun setupSundayFirst() {
-        binding.settingsSundayFirst.isChecked = config.isSundayFirst
-        binding.settingsSundayFirstHolder.setOnClickListener {
-            binding.settingsSundayFirst.toggle()
-            config.isSundayFirst = binding.settingsSundayFirst.isChecked
+    private fun setupStartWeekOn() {
+        val items = arrayListOf(
+            RadioItem(6, getString(org.fossify.commons.R.string.sunday)),
+            RadioItem(0, getString(org.fossify.commons.R.string.monday)),
+            RadioItem(1, getString(org.fossify.commons.R.string.tuesday)),
+            RadioItem(2, getString(org.fossify.commons.R.string.wednesday)),
+            RadioItem(3, getString(org.fossify.commons.R.string.thursday)),
+            RadioItem(4, getString(org.fossify.commons.R.string.friday)),
+            RadioItem(5, getString(org.fossify.commons.R.string.saturday)),
+        )
+
+        binding.settingsStartWeekOn.text = resources.getStringArray(org.fossify.commons.R.array.week_days)[config.firstDayOfWeek]
+        binding.settingsStartWeekOnHolder.setOnClickListener {
+            RadioGroupDialog(this@SettingsActivity, items, config.firstDayOfWeek) { day ->
+                val firstDayOfWeek = day as Int
+                config.firstDayOfWeek = firstDayOfWeek
+                binding.settingsStartWeekOn.text = resources.getStringArray(org.fossify.commons.R.array.week_days)[config.firstDayOfWeek]
+            }
         }
     }
 
diff --git a/app/src/main/kotlin/org/fossify/clock/dialogs/EditAlarmDialog.kt b/app/src/main/kotlin/org/fossify/clock/dialogs/EditAlarmDialog.kt
index e470246a..a90f5e7e 100644
--- a/app/src/main/kotlin/org/fossify/clock/dialogs/EditAlarmDialog.kt
+++ b/app/src/main/kotlin/org/fossify/clock/dialogs/EditAlarmDialog.kt
@@ -92,10 +92,7 @@ class EditAlarmDialog(val activity: SimpleActivity, val alarm: Alarm, val onDism
             editAlarm.setText(alarm.label)
 
             val dayLetters = activity.resources.getStringArray(org.fossify.commons.R.array.week_day_letters).toList() as ArrayList<String>
-            val dayIndexes = arrayListOf(0, 1, 2, 3, 4, 5, 6)
-            if (activity.config.isSundayFirst) {
-                dayIndexes.moveLastItemToFront()
-            }
+            val dayIndexes = activity.orderDaysList(arrayListOf(0, 1, 2, 3, 4, 5, 6))
 
             dayIndexes.forEach {
                 val pow = Math.pow(2.0, it.toDouble()).toInt()
diff --git a/app/src/main/kotlin/org/fossify/clock/extensions/Context.kt b/app/src/main/kotlin/org/fossify/clock/extensions/Context.kt
index 95057827..cfe4e783 100644
--- a/app/src/main/kotlin/org/fossify/clock/extensions/Context.kt
+++ b/app/src/main/kotlin/org/fossify/clock/extensions/Context.kt
@@ -548,20 +548,24 @@ fun Context.getAlarmSelectedDaysString(bitMask: Int): String {
     }
 }
 
+fun Context.orderDaysList(days: List<Int>): List<Int> {
+    if (config.firstDayOfWeek > 0) {
+        val range = (config.firstDayOfWeek..6).toList() + (0..<config.firstDayOfWeek).toList()
+        return days.slice(range)
+    } else {
+        return days
+    }
+}
+
 fun Context.firstDayOrder(bitMask: Int): Int {
     if (bitMask == TODAY_BIT) return -2
     if (bitMask == TOMORROW_BIT) return -1
 
-    val dayBits = arrayListOf(MONDAY_BIT, TUESDAY_BIT, WEDNESDAY_BIT, THURSDAY_BIT, FRIDAY_BIT, SATURDAY_BIT, SUNDAY_BIT)
-
-    val sundayFirst = baseConfig.isSundayFirst
-    if (sundayFirst) {
-        dayBits.moveLastItemToFront()
-    }
+    val dayBits = orderDaysList(arrayListOf(MONDAY_BIT, TUESDAY_BIT, WEDNESDAY_BIT, THURSDAY_BIT, FRIDAY_BIT, SATURDAY_BIT, SUNDAY_BIT))
 
-    dayBits.forEach { bit ->
+    dayBits.forEachIndexed { i, bit ->
         if (bitMask and bit != 0) {
-            return if (bit == SUNDAY_BIT && sundayFirst) 0 else bit
+            return i
         }
     }
 
diff --git a/app/src/main/kotlin/org/fossify/clock/helpers/Config.kt b/app/src/main/kotlin/org/fossify/clock/helpers/Config.kt
index f069d578..873006a7 100644
--- a/app/src/main/kotlin/org/fossify/clock/helpers/Config.kt
+++ b/app/src/main/kotlin/org/fossify/clock/helpers/Config.kt
@@ -11,6 +11,8 @@ import org.fossify.commons.extensions.getDefaultAlarmSound
 import org.fossify.commons.extensions.getDefaultAlarmTitle
 import org.fossify.commons.helpers.BaseConfig
 import org.fossify.commons.helpers.SORT_DESCENDING
+import java.util.Calendar
+import java.util.Locale
 
 class Config(context: Context) : BaseConfig(context) {
     companion object {
@@ -108,4 +110,11 @@ class Config(context: Context) : BaseConfig(context) {
     var lastDataExportPath: String
         get() = prefs.getString(LAST_DATA_EXPORT_PATH, "")!!
         set(lastDataExportPath) = prefs.edit().putString(LAST_DATA_EXPORT_PATH, lastDataExportPath).apply()
+
+    var firstDayOfWeek: Int
+        get() {
+            val defaultFirstDayOfWeek = Calendar.getInstance(Locale.getDefault()).firstDayOfWeek
+            return prefs.getInt(FIRST_DAY_OF_WEEK, getDayNumber(defaultFirstDayOfWeek))
+        }
+        set(firstDayOfWeek) = prefs.edit().putInt(FIRST_DAY_OF_WEEK, firstDayOfWeek).apply()
 }
diff --git a/app/src/main/kotlin/org/fossify/clock/helpers/Constants.kt b/app/src/main/kotlin/org/fossify/clock/helpers/Constants.kt
index 6473f2ec..92c67e1f 100644
--- a/app/src/main/kotlin/org/fossify/clock/helpers/Constants.kt
+++ b/app/src/main/kotlin/org/fossify/clock/helpers/Constants.kt
@@ -28,6 +28,7 @@ const val STOPWATCH_LAPS_SORT_BY = "stopwatch_laps_sort_by"
 const val WAS_INITIAL_WIDGET_SET_UP = "was_initial_widget_set_up"
 const val DATA_EXPORT_EXTENSION = ".json"
 const val LAST_DATA_EXPORT_PATH = "last_alarms_export_path"
+const val FIRST_DAY_OF_WEEK = "first_day_of_week"
 
 const val TABS_COUNT = 4
 const val EDITED_TIME_ZONE_SEPARATOR = ":"
@@ -126,16 +127,18 @@ fun formatTime(showSeconds: Boolean, use24HourFormat: Boolean, hours: Int, minut
     }
 }
 
+fun getDayNumber(calendarDay: Int): Int = (calendarDay + 5) % 7
+
 fun getTomorrowBit(): Int {
     val calendar = Calendar.getInstance()
     calendar.add(Calendar.DAY_OF_WEEK, 1)
-    val dayOfWeek = (calendar.get(Calendar.DAY_OF_WEEK) + 5) % 7
+    val dayOfWeek = getDayNumber(calendar.get(Calendar.DAY_OF_WEEK))
     return 2.0.pow(dayOfWeek).toInt()
 }
 
 fun getTodayBit(): Int {
     val calendar = Calendar.getInstance()
-    val dayOfWeek = (calendar.get(Calendar.DAY_OF_WEEK) + 5) % 7
+    val dayOfWeek = getDayNumber(calendar.get(Calendar.DAY_OF_WEEK))
     return 2.0.pow(dayOfWeek).toInt()
 }
 
diff --git a/app/src/main/res/layout/activity_settings.xml b/app/src/main/res/layout/activity_settings.xml
index 7471758c..0c8e057c 100644
--- a/app/src/main/res/layout/activity_settings.xml
+++ b/app/src/main/res/layout/activity_settings.xml
@@ -157,32 +157,39 @@
             </RelativeLayout>
 
             <RelativeLayout
-                android:id="@+id/settings_prevent_phone_from_sleeping_holder"
-                style="@style/SettingsHolderCheckboxStyle"
+                android:id="@+id/settings_start_week_on_holder"
+                style="@style/SettingsHolderTextViewStyle"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content">
 
-                <org.fossify.commons.views.MyAppCompatCheckbox
-                    android:id="@+id/settings_prevent_phone_from_sleeping"
-                    style="@style/SettingsCheckboxStyle"
+                <org.fossify.commons.views.MyTextView
+                    android:id="@+id/settings_start_week_on_label"
+                    style="@style/SettingsTextLabelStyle"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:text="@string/start_week_on" />
+                <org.fossify.commons.views.MyTextView
+                    android:id="@+id/settings_start_week_on"
+                    style="@style/SettingsTextValueStyle"
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
-                    android:text="@string/prevent_phone_from_sleeping" />
+                    android:layout_below="@+id/settings_start_week_on_label"
+                    tools:text="@string/monday" />
 
             </RelativeLayout>
 
             <RelativeLayout
-                android:id="@+id/settings_sunday_first_holder"
+                android:id="@+id/settings_prevent_phone_from_sleeping_holder"
                 style="@style/SettingsHolderCheckboxStyle"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content">
 
                 <org.fossify.commons.views.MyAppCompatCheckbox
-                    android:id="@+id/settings_sunday_first"
+                    android:id="@+id/settings_prevent_phone_from_sleeping"
                     style="@style/SettingsCheckboxStyle"
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
-                    android:text="@string/sunday_first" />
+                    android:text="@string/prevent_phone_from_sleeping" />
 
             </RelativeLayout>