fix: depreciation start date ux fixes (#23339)

diff --git a/erpnext/assets/doctype/asset/asset.js b/erpnext/assets/doctype/asset/asset.js
index fba20c0..7ad164a 100644
--- a/erpnext/assets/doctype/asset/asset.js
+++ b/erpnext/assets/doctype/asset/asset.js
@@ -252,13 +252,6 @@
 		})
 	},
 
-	available_for_use_date: function(frm) {
-		$.each(frm.doc.finance_books || [], function(i, d) {
-			if(!d.depreciation_start_date) d.depreciation_start_date = frm.doc.available_for_use_date;
-		});
-		refresh_field("finance_books");
-	},
-
 	is_existing_asset: function(frm) {
 		frm.trigger("toggle_reference_doc");
 		// frm.toggle_reqd("next_depreciation_date", (!frm.doc.is_existing_asset && frm.doc.calculate_depreciation));
@@ -438,6 +431,15 @@
 		}
 
 		frappe.flags.dont_change_rate = false;
+	},
+
+	depreciation_start_date: function(frm, cdt, cdn) {
+		const book = locals[cdt][cdn];
+		if (frm.doc.available_for_use_date && book.depreciation_start_date == frm.doc.available_for_use_date) {
+			frappe.msgprint(__(`Depreciation Posting Date should not be equal to Available for Use Date.`));
+			book.depreciation_start_date = "";
+			frm.refresh_field("finance_books");
+		}
 	}
 });
 
diff --git a/erpnext/assets/doctype/asset/asset.py b/erpnext/assets/doctype/asset/asset.py
index 9d08d92..72debb7 100644
--- a/erpnext/assets/doctype/asset/asset.py
+++ b/erpnext/assets/doctype/asset/asset.py
@@ -6,7 +6,7 @@
 import frappe, erpnext, math, json
 from frappe import _
 from six import string_types
-from frappe.utils import flt, add_months, cint, nowdate, getdate, today, date_diff, month_diff, add_days
+from frappe.utils import flt, add_months, cint, nowdate, getdate, today, date_diff, month_diff, add_days, get_last_day
 from frappe.model.document import Document
 from erpnext.assets.doctype.asset_category.asset_category import get_asset_category_account
 from erpnext.assets.doctype.asset.depreciation \
@@ -83,6 +83,11 @@
 		if not self.available_for_use_date:
 			frappe.throw(_("Available for use date is required"))
 
+		for d in self.finance_books:
+			if d.depreciation_start_date == self.available_for_use_date:
+				frappe.throw(_("Row #{}: Depreciation Posting Date should not be equal to Available for Use Date.").format(d.idx),
+					title=_("Incorrect Date"))
+
 	def set_missing_values(self):
 		if not self.asset_category:
 			self.asset_category = frappe.get_cached_value("Item", self.item_code, "asset_category")
@@ -294,7 +299,7 @@
 		if not row.depreciation_start_date:
 			if not self.available_for_use_date:
 				frappe.throw(_("Row {0}: Depreciation Start Date is required").format(row.idx))
-			row.depreciation_start_date = self.available_for_use_date
+			row.depreciation_start_date = get_last_day(self.available_for_use_date)
 
 		if not self.is_existing_asset:
 			self.opening_accumulated_depreciation = 0
diff --git a/erpnext/assets/doctype/asset/test_asset.py b/erpnext/assets/doctype/asset/test_asset.py
index aed78e7..52039c1 100644
--- a/erpnext/assets/doctype/asset/test_asset.py
+++ b/erpnext/assets/doctype/asset/test_asset.py
@@ -371,19 +371,18 @@
 		asset_name = frappe.db.get_value("Asset", {"purchase_receipt": pr.name}, 'name')
 		asset = frappe.get_doc('Asset', asset_name)
 		asset.calculate_depreciation = 1
-		asset.available_for_use_date = nowdate()
-		asset.purchase_date = nowdate()
+		asset.available_for_use_date = '2020-01-01'
+		asset.purchase_date = '2020-01-01'
 		asset.append("finance_books", {
 			"expected_value_after_useful_life": 10000,
 			"depreciation_method": "Straight Line",
-			"total_number_of_depreciations": 3,
-			"frequency_of_depreciation": 10,
-			"depreciation_start_date": nowdate()
+			"total_number_of_depreciations": 10,
+			"frequency_of_depreciation": 1
 		})
 		asset.insert()
 		asset.submit()
 
-		post_depreciation_entries(date=add_months(nowdate(), 10))
+		post_depreciation_entries(date=add_months('2020-01-01', 4))
 
 		scrap_asset(asset.name)
 
@@ -392,9 +391,9 @@
 		self.assertTrue(asset.journal_entry_for_scrap)
 
 		expected_gle = (
-			("_Test Accumulated Depreciations - _TC", 30000.0, 0.0),
+			("_Test Accumulated Depreciations - _TC", 36000.0, 0.0),
 			("_Test Fixed Asset - _TC", 0.0, 100000.0),
-			("_Test Gain/Loss on Asset Disposal - _TC", 70000.0, 0.0)
+			("_Test Gain/Loss on Asset Disposal - _TC", 64000.0, 0.0)
 		)
 
 		gle = frappe.db.sql("""select account, debit, credit from `tabGL Entry`
@@ -466,8 +465,7 @@
 			"expected_value_after_useful_life": 10000,
 			"depreciation_method": "Straight Line",
 			"total_number_of_depreciations": 3,
-			"frequency_of_depreciation": 10,
-			"depreciation_start_date": "2020-06-06"
+			"frequency_of_depreciation": 10
 		})
 		asset.insert()
 		accumulated_depreciation_after_full_schedule = \
diff --git a/erpnext/assets/doctype/asset_finance_book/asset_finance_book.json b/erpnext/assets/doctype/asset_finance_book/asset_finance_book.json
index c80f95e..79fcb95 100644
--- a/erpnext/assets/doctype/asset_finance_book/asset_finance_book.json
+++ b/erpnext/assets/doctype/asset_finance_book/asset_finance_book.json
@@ -1,347 +1,99 @@
 {
- "allow_copy": 0, 
- "allow_events_in_timeline": 0, 
- "allow_guest_to_view": 0, 
- "allow_import": 0, 
- "allow_rename": 0, 
- "beta": 0, 
- "creation": "2018-05-08 14:44:37.095570", 
- "custom": 0, 
- "docstatus": 0, 
- "doctype": "DocType", 
- "document_type": "", 
- "editable_grid": 1, 
- "engine": "InnoDB", 
+ "actions": [],
+ "creation": "2018-05-08 14:44:37.095570",
+ "doctype": "DocType",
+ "editable_grid": 1,
+ "engine": "InnoDB",
+ "field_order": [
+  "finance_book",
+  "depreciation_method",
+  "total_number_of_depreciations",
+  "column_break_5",
+  "frequency_of_depreciation",
+  "depreciation_start_date",
+  "expected_value_after_useful_life",
+  "value_after_depreciation",
+  "rate_of_depreciation"
+ ],
  "fields": [
   {
-   "allow_bulk_edit": 0, 
-   "allow_in_quick_entry": 0, 
-   "allow_on_submit": 0, 
-   "bold": 0, 
-   "collapsible": 0, 
-   "columns": 0, 
-   "depends_on": "", 
-   "fetch_if_empty": 0, 
-   "fieldname": "finance_book", 
-   "fieldtype": "Link", 
-   "hidden": 0, 
-   "ignore_user_permissions": 0, 
-   "ignore_xss_filter": 0, 
-   "in_filter": 0, 
-   "in_global_search": 0, 
-   "in_list_view": 1, 
-   "in_standard_filter": 0, 
-   "label": "Finance Book", 
-   "length": 0, 
-   "no_copy": 0, 
-   "options": "Finance Book", 
-   "permlevel": 0, 
-   "precision": "", 
-   "print_hide": 0, 
-   "print_hide_if_no_value": 0, 
-   "read_only": 0, 
-   "remember_last_selected_value": 0, 
-   "report_hide": 0, 
-   "reqd": 0, 
-   "search_index": 0, 
-   "set_only_once": 0, 
-   "translatable": 0, 
-   "unique": 0
-  }, 
+   "fieldname": "finance_book",
+   "fieldtype": "Link",
+   "in_list_view": 1,
+   "label": "Finance Book",
+   "options": "Finance Book"
+  },
   {
-   "allow_bulk_edit": 0, 
-   "allow_in_quick_entry": 0, 
-   "allow_on_submit": 0, 
-   "bold": 0, 
-   "collapsible": 0, 
-   "columns": 0, 
-   "fetch_if_empty": 0, 
-   "fieldname": "depreciation_method", 
-   "fieldtype": "Select", 
-   "hidden": 0, 
-   "ignore_user_permissions": 0, 
-   "ignore_xss_filter": 0, 
-   "in_filter": 0, 
-   "in_global_search": 0, 
-   "in_list_view": 1, 
-   "in_standard_filter": 0, 
-   "label": "Depreciation Method", 
-   "length": 0, 
-   "no_copy": 0, 
-   "options": "\nStraight Line\nDouble Declining Balance\nWritten Down Value\nManual", 
-   "permlevel": 0, 
-   "precision": "", 
-   "print_hide": 0, 
-   "print_hide_if_no_value": 0, 
-   "read_only": 0, 
-   "remember_last_selected_value": 0, 
-   "report_hide": 0, 
-   "reqd": 1, 
-   "search_index": 0, 
-   "set_only_once": 0, 
-   "translatable": 0, 
-   "unique": 0
-  }, 
+   "fieldname": "depreciation_method",
+   "fieldtype": "Select",
+   "in_list_view": 1,
+   "label": "Depreciation Method",
+   "options": "\nStraight Line\nDouble Declining Balance\nWritten Down Value\nManual",
+   "reqd": 1
+  },
   {
-   "allow_bulk_edit": 0, 
-   "allow_in_quick_entry": 0, 
-   "allow_on_submit": 0, 
-   "bold": 0, 
-   "collapsible": 0, 
-   "columns": 0, 
-   "fetch_if_empty": 0, 
-   "fieldname": "total_number_of_depreciations", 
-   "fieldtype": "Int", 
-   "hidden": 0, 
-   "ignore_user_permissions": 0, 
-   "ignore_xss_filter": 0, 
-   "in_filter": 0, 
-   "in_global_search": 0, 
-   "in_list_view": 1, 
-   "in_standard_filter": 0, 
-   "label": "Total Number of Depreciations", 
-   "length": 0, 
-   "no_copy": 0, 
-   "permlevel": 0, 
-   "precision": "", 
-   "print_hide": 0, 
-   "print_hide_if_no_value": 0, 
-   "read_only": 0, 
-   "remember_last_selected_value": 0, 
-   "report_hide": 0, 
-   "reqd": 1, 
-   "search_index": 0, 
-   "set_only_once": 0, 
-   "translatable": 0, 
-   "unique": 0
-  }, 
+   "fieldname": "total_number_of_depreciations",
+   "fieldtype": "Int",
+   "in_list_view": 1,
+   "label": "Total Number of Depreciations",
+   "reqd": 1
+  },
   {
-   "allow_bulk_edit": 0, 
-   "allow_in_quick_entry": 0, 
-   "allow_on_submit": 0, 
-   "bold": 0, 
-   "collapsible": 0, 
-   "columns": 0, 
-   "fetch_if_empty": 0, 
-   "fieldname": "column_break_5", 
-   "fieldtype": "Column Break", 
-   "hidden": 0, 
-   "ignore_user_permissions": 0, 
-   "ignore_xss_filter": 0, 
-   "in_filter": 0, 
-   "in_global_search": 0, 
-   "in_list_view": 0, 
-   "in_standard_filter": 0, 
-   "label": "", 
-   "length": 0, 
-   "no_copy": 0, 
-   "permlevel": 0, 
-   "precision": "", 
-   "print_hide": 0, 
-   "print_hide_if_no_value": 0, 
-   "read_only": 0, 
-   "remember_last_selected_value": 0, 
-   "report_hide": 0, 
-   "reqd": 0, 
-   "search_index": 0, 
-   "set_only_once": 0, 
-   "translatable": 0, 
-   "unique": 0
-  }, 
+   "fieldname": "column_break_5",
+   "fieldtype": "Column Break"
+  },
   {
-   "allow_bulk_edit": 0, 
-   "allow_in_quick_entry": 0, 
-   "allow_on_submit": 0, 
-   "bold": 0, 
-   "collapsible": 0, 
-   "columns": 0, 
-   "fetch_if_empty": 0, 
-   "fieldname": "frequency_of_depreciation", 
-   "fieldtype": "Int", 
-   "hidden": 0, 
-   "ignore_user_permissions": 0, 
-   "ignore_xss_filter": 0, 
-   "in_filter": 0, 
-   "in_global_search": 0, 
-   "in_list_view": 1, 
-   "in_standard_filter": 0, 
-   "label": "Frequency of Depreciation (Months)", 
-   "length": 0, 
-   "no_copy": 0, 
-   "permlevel": 0, 
-   "precision": "", 
-   "print_hide": 0, 
-   "print_hide_if_no_value": 0, 
-   "read_only": 0, 
-   "remember_last_selected_value": 0, 
-   "report_hide": 0, 
-   "reqd": 1, 
-   "search_index": 0, 
-   "set_only_once": 0, 
-   "translatable": 0, 
-   "unique": 0
-  }, 
+   "fieldname": "frequency_of_depreciation",
+   "fieldtype": "Int",
+   "in_list_view": 1,
+   "label": "Frequency of Depreciation (Months)",
+   "reqd": 1
+  },
   {
-   "allow_bulk_edit": 0, 
-   "allow_in_quick_entry": 0, 
-   "allow_on_submit": 0, 
-   "bold": 0, 
-   "collapsible": 0, 
-   "columns": 0, 
-   "depends_on": "eval:parent.doctype == 'Asset'", 
-   "fetch_if_empty": 0, 
-   "fieldname": "depreciation_start_date", 
-   "fieldtype": "Date", 
-   "hidden": 0, 
-   "ignore_user_permissions": 0, 
-   "ignore_xss_filter": 0, 
-   "in_filter": 0, 
-   "in_global_search": 0, 
-   "in_list_view": 1, 
-   "in_standard_filter": 0, 
-   "label": "Depreciation Start Date", 
-   "length": 0, 
-   "no_copy": 0, 
-   "permlevel": 0, 
-   "precision": "", 
-   "print_hide": 0, 
-   "print_hide_if_no_value": 0, 
-   "read_only": 0, 
-   "remember_last_selected_value": 0, 
-   "report_hide": 0, 
-   "reqd": 0, 
-   "search_index": 0, 
-   "set_only_once": 0, 
-   "translatable": 0, 
-   "unique": 0
-  }, 
+   "depends_on": "eval:parent.doctype == 'Asset'",
+   "fieldname": "depreciation_start_date",
+   "fieldtype": "Date",
+   "in_list_view": 1,
+   "label": "Depreciation Posting Date",
+   "reqd": 1
+  },
   {
-   "allow_bulk_edit": 0, 
-   "allow_in_quick_entry": 0, 
-   "allow_on_submit": 0, 
-   "bold": 0, 
-   "collapsible": 0, 
-   "columns": 0, 
-   "default": "0", 
-   "depends_on": "eval:parent.doctype == 'Asset'", 
-   "fetch_if_empty": 0, 
-   "fieldname": "expected_value_after_useful_life", 
-   "fieldtype": "Currency", 
-   "hidden": 0, 
-   "ignore_user_permissions": 0, 
-   "ignore_xss_filter": 0, 
-   "in_filter": 0, 
-   "in_global_search": 0, 
-   "in_list_view": 0, 
-   "in_standard_filter": 0, 
-   "label": "Expected Value After Useful Life", 
-   "length": 0, 
-   "no_copy": 0, 
-   "options": "Company:company:default_currency", 
-   "permlevel": 0, 
-   "precision": "", 
-   "print_hide": 0, 
-   "print_hide_if_no_value": 0, 
-   "read_only": 0, 
-   "remember_last_selected_value": 0, 
-   "report_hide": 0, 
-   "reqd": 0, 
-   "search_index": 0, 
-   "set_only_once": 0, 
-   "translatable": 0, 
-   "unique": 0
-  }, 
+   "default": "0",
+   "depends_on": "eval:parent.doctype == 'Asset'",
+   "fieldname": "expected_value_after_useful_life",
+   "fieldtype": "Currency",
+   "label": "Expected Value After Useful Life",
+   "options": "Company:company:default_currency"
+  },
   {
-   "allow_bulk_edit": 0, 
-   "allow_in_quick_entry": 0, 
-   "allow_on_submit": 0, 
-   "bold": 0, 
-   "collapsible": 0, 
-   "columns": 0, 
-   "fetch_if_empty": 0, 
-   "fieldname": "value_after_depreciation", 
-   "fieldtype": "Currency", 
-   "hidden": 1, 
-   "ignore_user_permissions": 0, 
-   "ignore_xss_filter": 0, 
-   "in_filter": 0, 
-   "in_global_search": 0, 
-   "in_list_view": 0, 
-   "in_standard_filter": 0, 
-   "label": "Value After Depreciation", 
-   "length": 0, 
-   "no_copy": 1, 
-   "options": "Company:company:default_currency", 
-   "permlevel": 0, 
-   "precision": "", 
-   "print_hide": 1, 
-   "print_hide_if_no_value": 0, 
-   "read_only": 1, 
-   "remember_last_selected_value": 0, 
-   "report_hide": 0, 
-   "reqd": 0, 
-   "search_index": 0, 
-   "set_only_once": 0, 
-   "translatable": 0, 
-   "unique": 0
-  }, 
+   "fieldname": "value_after_depreciation",
+   "fieldtype": "Currency",
+   "hidden": 1,
+   "label": "Value After Depreciation",
+   "no_copy": 1,
+   "options": "Company:company:default_currency",
+   "print_hide": 1,
+   "read_only": 1
+  },
   {
-   "allow_bulk_edit": 0, 
-   "allow_in_quick_entry": 0, 
-   "allow_on_submit": 0, 
-   "bold": 0, 
-   "collapsible": 0, 
-   "columns": 0, 
-   "depends_on": "eval:doc.depreciation_method == 'Written Down Value'", 
-   "description": "In Percentage", 
-   "fetch_if_empty": 0, 
-   "fieldname": "rate_of_depreciation", 
-   "fieldtype": "Percent", 
-   "hidden": 0, 
-   "ignore_user_permissions": 0, 
-   "ignore_xss_filter": 0, 
-   "in_filter": 0, 
-   "in_global_search": 0, 
-   "in_list_view": 0, 
-   "in_standard_filter": 0, 
-   "label": "Rate of Depreciation", 
-   "length": 0, 
-   "no_copy": 0, 
-   "permlevel": 0, 
-   "precision": "", 
-   "print_hide": 0, 
-   "print_hide_if_no_value": 0, 
-   "read_only": 0, 
-   "remember_last_selected_value": 0, 
-   "report_hide": 0, 
-   "reqd": 0, 
-   "search_index": 0, 
-   "set_only_once": 0, 
-   "translatable": 0, 
-   "unique": 0
+   "depends_on": "eval:doc.depreciation_method == 'Written Down Value'",
+   "description": "In Percentage",
+   "fieldname": "rate_of_depreciation",
+   "fieldtype": "Percent",
+   "label": "Rate of Depreciation"
   }
- ], 
- "has_web_view": 0, 
- "hide_toolbar": 0, 
- "idx": 0, 
- "in_create": 0, 
- "is_submittable": 0, 
- "issingle": 0, 
- "istable": 1, 
- "max_attachments": 0, 
- "modified": "2019-04-09 19:45:14.523488", 
- "modified_by": "Administrator", 
- "module": "Assets", 
- "name": "Asset Finance Book", 
- "name_case": "", 
- "owner": "Administrator", 
- "permissions": [], 
- "quick_entry": 1, 
- "read_only": 0, 
- "show_name_in_global_search": 0, 
- "sort_field": "modified", 
- "sort_order": "DESC", 
- "track_changes": 1, 
- "track_seen": 0, 
- "track_views": 0
+ ],
+ "index_web_pages_for_search": 1,
+ "istable": 1,
+ "links": [],
+ "modified": "2020-09-16 12:11:30.631788",
+ "modified_by": "Administrator",
+ "module": "Assets",
+ "name": "Asset Finance Book",
+ "owner": "Administrator",
+ "permissions": [],
+ "quick_entry": 1,
+ "sort_field": "modified",
+ "sort_order": "DESC",
+ "track_changes": 1
 }
\ No newline at end of file
diff --git a/erpnext/assets/doctype/asset_movement/test_asset_movement.py b/erpnext/assets/doctype/asset_movement/test_asset_movement.py
index c3755a3..cddee5f 100644
--- a/erpnext/assets/doctype/asset_movement/test_asset_movement.py
+++ b/erpnext/assets/doctype/asset_movement/test_asset_movement.py
@@ -32,8 +32,7 @@
 			"next_depreciation_date": "2020-12-31",
 			"depreciation_method": "Straight Line",
 			"total_number_of_depreciations": 3,
-			"frequency_of_depreciation": 10,
-			"depreciation_start_date": "2020-06-06"
+			"frequency_of_depreciation": 10
 		})
 
 		if asset.docstatus == 0:
@@ -82,8 +81,7 @@
 			"next_depreciation_date": "2020-12-31",
 			"depreciation_method": "Straight Line",
 			"total_number_of_depreciations": 3,
-			"frequency_of_depreciation": 10,
-			"depreciation_start_date": "2020-06-06"
+			"frequency_of_depreciation": 10
 		})
 		if asset.docstatus == 0:
 			asset.submit()
diff --git a/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py b/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py
index 67161aa..1e7153e 100644
--- a/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py
+++ b/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py
@@ -494,8 +494,7 @@
 			"expected_value_after_useful_life": 10,
 			"depreciation_method": "Straight Line",
 			"total_number_of_depreciations": 3,
-			"frequency_of_depreciation": 1,
-			"depreciation_start_date": frappe.utils.nowdate()
+			"frequency_of_depreciation": 1
 		})
 		asset.submit()