diff --git a/packages/localization/package.json b/packages/localization/package.json
index 556e5500ae86..221042266a73 100644
--- a/packages/localization/package.json
+++ b/packages/localization/package.json
@@ -39,7 +39,7 @@
     "resolve": "^1.20.0"
   },
   "dependencies": {
-    "@types/openui5": "^1.113.0",
+    "@types/openui5": "^1.146.0",
     "@ui5/webcomponents-base": "2.22.0-rc.0"
   }
 }
diff --git a/packages/localization/src/DateFormat.ts b/packages/localization/src/DateFormat.ts
index da6649603374..5596e83b7f92 100644
--- a/packages/localization/src/DateFormat.ts
+++ b/packages/localization/src/DateFormat.ts
@@ -1,8 +1,42 @@
 import type DateFormatT from "sap/ui/core/format/DateFormat";
 // @ts-ignore
 import DateFormatNative from "./sap/ui/core/format/DateFormat.js";
+import getLocale from "@ui5/webcomponents-base/dist/locale/getLocale.js";
+import LocaleWrapped from "./Locale.js";
+import type CalendarWeekNumbering from "sap/base/i18n/date/CalendarWeekNumbering";
+import type CalendarType from "sap/base/i18n/date/CalendarType";
+
+type DateFormatOptions = {
+	calendarWeekNumbering?: CalendarWeekNumbering | keyof typeof CalendarWeekNumbering;
+	firstDayOfWeek?: int;
+	minimalDaysInFirstWeek?: int;
+	format?: string;
+	pattern?: string;
+	style?: string;
+	strictParsing?: boolean;
+	relative?: boolean;
+	relativeRange?: int[];
+	relativeScale?: string;
+	relativeStyle?: string;
+	interval?: boolean;
+	intervalDelimiter?: string;
+	singleIntervalValue?: boolean;
+	UTC?: boolean;
+	calendarType?: CalendarType | keyof typeof CalendarType;
+};
 
 const DateFormatWrapped = DateFormatNative as typeof DateFormatT;
-class DateFormat extends DateFormatWrapped {}
+
+class DateFormat extends DateFormatWrapped {
+	static getDateInstance(oFormatOptions?: DateFormatOptions, oLocale?: LocaleWrapped): DateFormat;
+	static getDateInstance(oLocale?: LocaleWrapped): DateFormat;
+	static getDateInstance(oFormatOptionsOrLocale?: DateFormatOptions | LocaleWrapped, oLocale?: LocaleWrapped): DateFormat {
+		if (oFormatOptionsOrLocale instanceof LocaleWrapped) {
+			return DateFormatWrapped.getDateInstance(undefined, oFormatOptionsOrLocale);
+		}
+		const nativeLocale = oLocale ?? new LocaleWrapped(getLocale().toString());
+		return DateFormatWrapped.getDateInstance(oFormatOptionsOrLocale, nativeLocale);
+	}
+}
 
 export default DateFormat;
diff --git a/packages/localization/src/Locale.ts b/packages/localization/src/Locale.ts
new file mode 100644
index 000000000000..79a0b1dc0f12
--- /dev/null
+++ b/packages/localization/src/Locale.ts
@@ -0,0 +1,8 @@
+import type LocaleOpenUI5T from "sap/ui/core/Locale";
+// @ts-ignore
+import LocaleNative from "./sap/ui/core/Locale.js";
+
+const LocaleWrapped = LocaleNative as typeof LocaleOpenUI5T;
+class Locale extends LocaleWrapped { }
+
+export default Locale;
diff --git a/packages/localization/src/dates/convertMonthNumbersToMonthNames.ts b/packages/localization/src/dates/convertMonthNumbersToMonthNames.ts
index 21c79a55115a..40b2fd16f9d1 100644
--- a/packages/localization/src/dates/convertMonthNumbersToMonthNames.ts
+++ b/packages/localization/src/dates/convertMonthNumbersToMonthNames.ts
@@ -15,8 +15,8 @@ import getCachedLocaleDataInstance from "../getCachedLocaleDataInstance.js";
 const convertMonthNumbersToMonthNames = (firstMonth: number, lastMonth: number, calendarType?: `${CalendarType}`) => {
 	const localeData = getCachedLocaleDataInstance(getLocale());
 	const pattern = localeData.getIntervalPattern("");
-	const secondaryMonthsNames = localeData.getMonthsStandAlone("abbreviated", calendarType) as Array<string>;
-	const secondaryMonthsNamesWide = localeData.getMonthsStandAlone("wide", calendarType) as Array<string>;
+	const secondaryMonthsNames = localeData.getMonthsStandAlone("abbreviated", calendarType);
+	const secondaryMonthsNamesWide = localeData.getMonthsStandAlone("wide", calendarType);
 
 	if (firstMonth === lastMonth) {
 		return {
diff --git a/packages/localization/src/getCachedLocaleDataInstance.ts b/packages/localization/src/getCachedLocaleDataInstance.ts
index 169b4d6c2dba..38542ca57107 100644
--- a/packages/localization/src/getCachedLocaleDataInstance.ts
+++ b/packages/localization/src/getCachedLocaleDataInstance.ts
@@ -6,6 +6,8 @@ const cache = new Map<Locale, LocaleData>();
 
 const getCachedLocaleDataInstance = (locale: Locale) => {
 	if (!cache.has(locale)) {
+		// @ts-expect-error - The LocaleData constructor expects a LocaleT, but we are passing a Locale. This is a known issue and can be ignored for now.
+		// eslint-disable-next-line @typescript-eslint/no-unsafe-argument
 		cache.set(locale, new LocaleData(locale as unknown as LocaleT));
 	}
 
diff --git a/packages/localization/src/locale/getLocaleData.ts b/packages/localization/src/locale/getLocaleData.ts
index 437c0a1c1056..6e2ac429ac26 100644
--- a/packages/localization/src/locale/getLocaleData.ts
+++ b/packages/localization/src/locale/getLocaleData.ts
@@ -19,6 +19,8 @@ const getLocaleData = async (lang: string): Promise<LocaleData> => {
 
 	if (!instances.has(localeLang)) {
 		await fetchCldr(locale.getLanguage(), locale.getRegion(), locale.getScript());
+		// @ts-expect-error - The LocaleData constructor expects a LocaleT, but we are passing a Locale. This is a known issue and can be ignored for now.
+		// eslint-disable-next-line @typescript-eslint/no-unsafe-argument
 		instances.set(localeLang, new LocaleData(locale as unknown as LocaleT));
 	}
 
diff --git a/packages/localization/src/sap/base/i18n/Formatting.ts b/packages/localization/src/sap/base/i18n/Formatting.ts
index 812e7105c4d9..23a868956a11 100644
--- a/packages/localization/src/sap/base/i18n/Formatting.ts
+++ b/packages/localization/src/sap/base/i18n/Formatting.ts
@@ -1,8 +1,8 @@
 import { getLegacyDateCalendarCustomizing } from "@ui5/webcomponents-base/dist/config/FormatSettings.js";
-import { getLanguage } from "@ui5/webcomponents-base/dist/config/Language.js";
 import { getCalendarType } from "@ui5/webcomponents-base/dist/config/CalendarType.js";
+import getLocale from "@ui5/webcomponents-base/dist/locale/getLocale.js";
 
-const emptyFn = () => {};
+const emptyFn = () => { };
 
 /**
  * OpenUI5 Formatting Shim
@@ -10,7 +10,7 @@ const emptyFn = () => {};
 const Formatting = {
 	getABAPDateFormat: emptyFn,
 	getCustomIslamicCalendarData: getLegacyDateCalendarCustomizing,
-	getLanguageTag: () => getLanguage() || "en",
+	getLanguageTag: () => getLocale().toString(),
 	getCalendarType,
 	getTrailingCurrencyCode: () => true,
 	getCustomLocaleData: () => ({}),
diff --git a/packages/localization/src/sap/base/i18n/Localization.ts b/packages/localization/src/sap/base/i18n/Localization.ts
index 518ae14c0ffc..3625ed49054c 100644
--- a/packages/localization/src/sap/base/i18n/Localization.ts
+++ b/packages/localization/src/sap/base/i18n/Localization.ts
@@ -1,5 +1,5 @@
-import { getLanguage } from "@ui5/webcomponents-base/dist/config/Language.js";
 import { getTimezone as getConfigTimezone } from "@ui5/webcomponents-base/dist/config/Timezone.js";
+import getLocale from "@ui5/webcomponents-base/dist/locale/getLocale.js";
 
 const M_ISO639_OLD_TO_NEW = {
 	"iw": "he",
@@ -12,7 +12,7 @@ const getModernLanguage = (sLanguage: string) => {
 
 const Localization = {
 	getModernLanguage,
-	getLanguageTag: () => getLanguage() || "en",
+	getLanguageTag: () => getLocale().toString(),
 	getTimezone: () => getConfigTimezone() || Intl.DateTimeFormat().resolvedOptions().timeZone,
 	setTimezone: () => {},
 };
diff --git a/packages/main/src/DayPicker.ts b/packages/main/src/DayPicker.ts
index 6fad0fa4e087..affaeaaca9a5 100644
--- a/packages/main/src/DayPicker.ts
+++ b/packages/main/src/DayPicker.ts
@@ -233,8 +233,8 @@ class DayPicker extends CalendarPart implements ICalendarPicker {
 
 		const firstDayOfWeek = this._getFirstDayOfWeek();
 		const specialCalendarDates = this._specialCalendarDates;
-		const monthsNames = localeData.getMonths("wide", this._primaryCalendarType) as Array<string>;
-		const secondaryMonthsNames = this.hasSecondaryCalendarType ? localeData.getMonths("wide", this.secondaryCalendarType) as Array<string> : [];
+		const monthsNames = localeData.getMonths("wide", this._primaryCalendarType);
+		const secondaryMonthsNames = this.hasSecondaryCalendarType ? localeData.getMonths("wide", this.secondaryCalendarType) : [];
 		const nonWorkingDayLabel = DayPicker.i18nBundle.getText(DAY_PICKER_NON_WORKING_DAY);
 		const todayLabel = DayPicker.i18nBundle.getText(DAY_PICKER_TODAY);
 		const tempDate = this._getFirstDay(); // date that will be changed by 1 day 42 times
@@ -385,12 +385,12 @@ class DayPicker extends CalendarPart implements ICalendarPicker {
 
 		let dayOfTheWeek;
 
-		const aDayNamesWide = localeData.getDays("wide", this._primaryCalendarType) as Array<string>;
-		let aDayNamesAbbreviated = localeData.getDays("abbreviated", this._primaryCalendarType) as Array<string>;
+		const aDayNamesWide = localeData.getDays("wide", this._primaryCalendarType);
+		let aDayNamesAbbreviated = localeData.getDays("abbreviated", this._primaryCalendarType);
 		let dayName;
 
 		if (this.namesTooLong(aDayNamesAbbreviated)) {
-			aDayNamesAbbreviated = localeData.getDays("narrow", this._primaryCalendarType) as Array<string>;
+			aDayNamesAbbreviated = localeData.getDays("narrow", this._primaryCalendarType);
 		}
 
 		this._dayNames = [];
diff --git a/packages/main/src/MonthPicker.ts b/packages/main/src/MonthPicker.ts
index 881ab8d9bdc9..63a514d75b27 100644
--- a/packages/main/src/MonthPicker.ts
+++ b/packages/main/src/MonthPicker.ts
@@ -46,7 +46,7 @@ type Month = {
 	selected: boolean,
 	ariaSelected: boolean,
 	name: string,
-	nameInSecType: string,
+	nameInSecType: string | undefined,
 	disabled: boolean,
 	ariaDisabled: boolean | undefined,
 	classes: string,
@@ -191,7 +191,7 @@ class MonthPicker extends CalendarPart implements ICalendarPicker {
 				selected: isSelected || isSelectedBetween,
 				ariaSelected: isSelected || isSelectedBetween,
 				name: monthsNames[i],
-				nameInSecType: this.hasSecondaryCalendarType && this._getDisplayedSecondaryMonthText(timestamp).text,
+				nameInSecType: this.hasSecondaryCalendarType ? this._getDisplayedSecondaryMonthText(timestamp).text : undefined,
 				disabled: isDisabled,
 				ariaDisabled: isDisabled,
 				classes: "ui5-mp-item",
diff --git a/packages/main/src/YearPicker.ts b/packages/main/src/YearPicker.ts
index c487eb23daf6..4780c867b0c4 100644
--- a/packages/main/src/YearPicker.ts
+++ b/packages/main/src/YearPicker.ts
@@ -2,7 +2,6 @@ import customElement from "@ui5/webcomponents-base/dist/decorators/customElement
 import property from "@ui5/webcomponents-base/dist/decorators/property.js";
 import event from "@ui5/webcomponents-base/dist/decorators/event-strict.js";
 import i18n from "@ui5/webcomponents-base/dist/decorators/i18n.js";
-import type LocaleT from "sap/ui/core/Locale";
 import DateFormat from "@ui5/webcomponents-localization/dist/DateFormat.js";
 import {
 	isEnter,
@@ -18,7 +17,6 @@ import {
 	isPageUp,
 	isPageDown,
 } from "@ui5/webcomponents-base/dist/Keys.js";
-import getLocale from "@ui5/webcomponents-base/dist/locale/getLocale.js";
 import transformDateToSecondaryType from "@ui5/webcomponents-localization/dist/dates/transformDateToSecondaryType.js";
 import CalendarDate from "@ui5/webcomponents-localization/dist/dates/CalendarDate.js";
 import type I18nBundle from "@ui5/webcomponents-base/dist/i18nBundle.js";
@@ -161,9 +159,8 @@ class YearPicker extends CalendarPart implements ICalendarPicker {
 
 	_buildYears() {
 		const pageSize = this._getPageSize();
-		const locale = getLocale() as unknown as LocaleT;
-		const oYearFormat = DateFormat.getDateInstance({ format: "y", calendarType: this._primaryCalendarType }, locale);
-		const oYearFormatInSecType = DateFormat.getDateInstance({ format: "y", calendarType: this.secondaryCalendarType }, locale);
+		const oYearFormat = DateFormat.getDateInstance({ format: "y", calendarType: this._primaryCalendarType });
+		const oYearFormatInSecType = DateFormat.getDateInstance({ format: "y", calendarType: this.secondaryCalendarType });
 
 		const calendarDate = this._calendarDate; // store the value of the expensive getter
 		const minDate = this._minDate; // store the value of the expensive getter
diff --git a/packages/main/src/YearRangePicker.ts b/packages/main/src/YearRangePicker.ts
index 6494deb8a3ca..713865f1daa3 100644
--- a/packages/main/src/YearRangePicker.ts
+++ b/packages/main/src/YearRangePicker.ts
@@ -2,7 +2,6 @@ import customElement from "@ui5/webcomponents-base/dist/decorators/customElement
 import property from "@ui5/webcomponents-base/dist/decorators/property.js";
 import event from "@ui5/webcomponents-base/dist/decorators/event-strict.js";
 import i18n from "@ui5/webcomponents-base/dist/decorators/i18n.js";
-import type LocaleT from "sap/ui/core/Locale";
 import DateFormat from "@ui5/webcomponents-localization/dist/DateFormat.js";
 import {
 	isEnter,
@@ -145,7 +144,7 @@ class YearRangePicker extends CalendarPart implements ICalendarPicker {
 	}
 
 	_shouldShowOneColumn() {
-		const locale = getLocale() as unknown as LocaleT;
+		const locale = getLocale();
 		const language = locale.getLanguage();
 		const longLanguages = ["zh", "ja", "ko", "bg", "mk", "ru"];
 
@@ -200,9 +199,8 @@ class YearRangePicker extends CalendarPart implements ICalendarPicker {
 	}
 
 	_getYearRanges() {
-		const locale = getLocale() as unknown as LocaleT;
-		const yearFormat = DateFormat.getDateInstance({ format: "y", calendarType: this._primaryCalendarType }, locale);
-		const yearFormatInSecType = DateFormat.getDateInstance({ format: "y", calendarType: this._secondaryCalendarType }, locale);
+		const yearFormat = DateFormat.getDateInstance({ format: "y", calendarType: this._primaryCalendarType });
+		const yearFormatInSecType = DateFormat.getDateInstance({ format: "y", calendarType: this._secondaryCalendarType });
 
 		const pageSize = this._getPageSize();
 		const rowSize = this._getRowSize();
diff --git a/yarn.lock b/yarn.lock
index e3d9aec34a2a..81a7a99047cb 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -6847,12 +6847,12 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/jquery@npm:*":
-  version: 3.5.16
-  resolution: "@types/jquery@npm:3.5.16"
+"@types/jquery@npm:~3.5.13":
+  version: 3.5.34
+  resolution: "@types/jquery@npm:3.5.34"
   dependencies:
     "@types/sizzle": "npm:*"
-  checksum: 10c0/f40f6528f91e52e2cf5c08ad9d0ed7aad4392b366e3b4228cd3e57d4e0d82c850f0694a9c2779065acb2353e372d337e2fb1dc6861c8c5849bd6538ce2f002e8
+  checksum: 10c0/c85eec82531912cc497c34daad3509cf54875a0457c64d82b4fe17a4a27a313150c0882b7dd345b7e98c9116e0bae64c3942b7a76f6edcd664efa701cd1f2d81
   languageName: node
   linkType: hard
 
@@ -7047,13 +7047,13 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/openui5@npm:^1.113.0":
-  version: 1.115.1
-  resolution: "@types/openui5@npm:1.115.1"
+"@types/openui5@npm:^1.146.0":
+  version: 1.146.0
+  resolution: "@types/openui5@npm:1.146.0"
   dependencies:
-    "@types/jquery": "npm:*"
-    "@types/qunit": "npm:*"
-  checksum: 10c0/4ca4c412cc363e66e9a7a180e5d9e9d31a0734e2c26ea818bc534adbb1e8dc6f6d464bb84872ee237ecc04a41e002284daef2e3ab8b8e99efac7415ab28debea
+    "@types/jquery": "npm:~3.5.13"
+    "@types/qunit": "npm:^2.5.4"
+  checksum: 10c0/c6b0a5c9d91ea5ce545a8b9acdbe963e0088f4957d3dd1abbedc20a6cca5dfc8f00e467e9f5495a9724ab2296928cb2b2e7a5ec3a583615cc37b272591ef5bc2
   languageName: node
   linkType: hard
 
@@ -7092,10 +7092,10 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/qunit@npm:*":
-  version: 2.19.6
-  resolution: "@types/qunit@npm:2.19.6"
-  checksum: 10c0/9c36a1ab9007ee4da5e04e635aea6b03cc35b09fe38fff4fd2f97a1725c567072fe69604ff5a17e09091b389d3d4d9162e25a44207430276f0b9f14475378548
+"@types/qunit@npm:^2.5.4":
+  version: 2.19.13
+  resolution: "@types/qunit@npm:2.19.13"
+  checksum: 10c0/47f31282083f5f278bf0e4e49522f382f10161358363c8bd309fae8f926a4732c456d4c77aedd25a33c4bcc7da86cea87fd7a96531806adb85ce01b4f38eae4a
   languageName: node
   linkType: hard
 
@@ -7772,7 +7772,7 @@ __metadata:
     "@babel/generator": "npm:^7.24.6"
     "@babel/parser": "npm:^7.24.6"
     "@openui5/sap.ui.core": "npm:1.146.0"
-    "@types/openui5": "npm:^1.113.0"
+    "@types/openui5": "npm:^1.146.0"
     "@ui5/webcomponents-base": "npm:2.22.0-rc.0"
     "@ui5/webcomponents-tools": "npm:2.22.0-rc.0"
     babel-plugin-amd-to-esm: "npm:^2.0.3"