diff --git a/frappe/core/doctype/system_settings/system_settings.json b/frappe/core/doctype/system_settings/system_settings.json
index 3e04643256..0af8f2e4be 100644
--- a/frappe/core/doctype/system_settings/system_settings.json
+++ b/frappe/core/doctype/system_settings/system_settings.json
@@ -17,10 +17,11 @@
   "date_and_number_format",
   "date_format",
   "time_format",
-  "column_break_7",
   "number_format",
+  "column_break_7",
   "float_precision",
   "currency_precision",
+  "week_starts_on",
   "sec_backup_limit",
   "backup_limit",
   "encrypt_backup",
@@ -477,12 +478,19 @@
    "fieldname": "disable_system_update_notification",
    "fieldtype": "Check",
    "label": "Disable System Update Notification"
+  },
+  {
+   "default": "Sunday",
+   "fieldname": "week_starts_on",
+   "fieldtype": "Select",
+   "label": "Week Starts On",
+   "options": "Sunday\nMonday\nTuesday\nWednesday\nThursday\nFriday\nSaturday"
   }
  ],
  "icon": "fa fa-cog",
  "issingle": 1,
  "links": [],
- "modified": "2021-11-29 18:09:53.601629",
+ "modified": "2022-01-04 11:28:34.881192",
  "modified_by": "Administrator",
  "module": "Core",
  "name": "System Settings",
@@ -499,5 +507,6 @@
  "quick_entry": 1,
  "sort_field": "modified",
  "sort_order": "ASC",
+ "states": [],
  "track_changes": 1
 }
\ No newline at end of file
diff --git a/frappe/desk/doctype/system_console/system_console.js b/frappe/desk/doctype/system_console/system_console.js
index 0fe3932671..06f04e8b32 100644
--- a/frappe/desk/doctype/system_console/system_console.js
+++ b/frappe/desk/doctype/system_console/system_console.js
@@ -100,5 +100,9 @@ frappe.ui.form.on('System Console', {
 				</tr></thead>
 				<tbody>${rows}</thead>`);
 		});
+	},
+
+	week_starts_on() {
+		frappe.app.setup_moment()
 	}
 });
diff --git a/frappe/public/js/frappe/desk.js b/frappe/public/js/frappe/desk.js
index 64767e1232..f9a9931c4c 100644
--- a/frappe/public/js/frappe/desk.js
+++ b/frappe/public/js/frappe/desk.js
@@ -275,11 +275,7 @@ frappe.Application = class Application {
 			this.set_globals();
 			this.sync_pages();
 			frappe.router.setup();
-			moment.locale("en");
-			moment.user_utc_offset = moment().utcOffset();
-			if(frappe.boot.timezone_info) {
-				moment.tz.add(frappe.boot.timezone_info);
-			}
+			this.setup_moment();
 			if(frappe.boot.print_css) {
 				frappe.dom.set_style(frappe.boot.print_css, "print-style");
 			}
@@ -628,6 +624,19 @@ frappe.Application = class Application {
 			}
 		});
 	}
+
+	setup_moment() {
+		moment.updateLocale('en', {
+			week : {
+				dow : frappe.datetime.get_week_starts_on_index(),
+			}
+		});
+		moment.locale("en");
+		moment.user_utc_offset = moment().utcOffset();
+		if(frappe.boot.timezone_info) {
+			moment.tz.add(frappe.boot.timezone_info);
+		}
+	}
 }
 
 frappe.get_module = function(m, default_module) {
diff --git a/frappe/public/js/frappe/utils/datetime.js b/frappe/public/js/frappe/utils/datetime.js
index 7bb6076b72..09e44d917d 100644
--- a/frappe/public/js/frappe/utils/datetime.js
+++ b/frappe/public/js/frappe/utils/datetime.js
@@ -254,6 +254,11 @@ $.extend(frappe.datetime, {
 		], true).isValid();
 	},
 
+	get_week_starts_on_index() {
+		const week_starts_on = frappe.sys_defaults.week_starts_on || "Sunday";
+		return moment.weekdays().indexOf(week_starts_on);
+	}
+
 });
 
 // Proxy for dateutil and get_today
diff --git a/frappe/utils/data.py b/frappe/utils/data.py
index 7a65a6f18a..9f9391b1fc 100644
--- a/frappe/utils/data.py
+++ b/frappe/utils/data.py
@@ -11,11 +11,26 @@ from code import compile_command
 from urllib.parse import quote, urljoin
 from frappe.desk.utils import slug
 from click import secho
+from enum import Enum
 
 DATE_FORMAT = "%Y-%m-%d"
 TIME_FORMAT = "%H:%M:%S.%f"
 DATETIME_FORMAT = DATE_FORMAT + " " + TIME_FORMAT
 
+class Weekday(Enum):
+	Sunday = 0
+	Monday = 1
+	Tuesday = 2
+	Wednesday = 3
+	Thursday = 4
+	Friday = 5
+	Saturday = 6
+
+def get_week_starts_on():
+	return frappe.get_system_settings('week_starts_on') or "Sunday"
+
+def get_start_of_week_index():
+	return Weekday[get_week_starts_on()].value
 
 def is_invalid_date_string(date_string):
 	# dateutil parser does not agree with dates like "0001-01-01" or "0000-00-00"
@@ -246,9 +261,22 @@ def get_quarter_start(dt, as_str=False):
 
 def get_first_day_of_week(dt, as_str=False):
 	dt = getdate(dt)
-	date = dt - datetime.timedelta(days=(dt.weekday() + 1) % 7)
+	date = dt - datetime.timedelta(days=get_week_start_offset_days(dt))
 	return date.strftime(DATE_FORMAT) if as_str else date
 
+def get_week_start_offset_days(dt):
+	current_day_index = get_normalized_weekday_index(dt)
+	start_of_week_index = get_start_of_week_index()
+
+	if current_day_index >= start_of_week_index:
+		return current_day_index - start_of_week_index
+	else:
+		return 7 - (start_of_week_index - current_day_index)
+
+def get_normalized_weekday_index(dt):
+	# starts Sunday with 0
+	return (dt.weekday() + 1) % 7
+
 def get_year_start(dt, as_str=False):
 	dt = getdate(dt)
 	date = datetime.date(dt.year, 1, 1)