diff --git a/l10n/messages.pot b/l10n/messages.pot
index 01710efedd..3601505f05 100644
--- a/l10n/messages.pot
+++ b/l10n/messages.pot
@@ -211,10 +211,6 @@ msgstr ""
 msgid "Frequently used"
 msgstr ""
 
-#. TRANSLATORS: This refers to global timezones in the timezone picker
-msgid "Global"
-msgstr ""
-
 msgid "Go back to the list"
 msgstr ""
 
@@ -416,9 +412,6 @@ msgstr ""
 msgid "Search emoji"
 msgstr ""
 
-msgid "Search for timezone"
-msgstr ""
-
 msgid "Search results"
 msgstr ""
 
diff --git a/package-lock.json b/package-lock.json
index b0edd8fc20..e4b4d58f65 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -21,7 +21,6 @@
         "@nextcloud/logger": "^3.0.2",
         "@nextcloud/router": "^3.0.1",
         "@nextcloud/sharing": "^0.3.0",
-        "@nextcloud/timezones": "^1.0.0",
         "@vuepic/vue-datepicker": "^11.0.2",
         "@vueuse/components": "^13.9.0",
         "@vueuse/core": "^13.9.0",
@@ -3523,18 +3522,6 @@
         "stylelint-config-recommended-vue": "^1.5.0"
       }
     },
-    "node_modules/@nextcloud/timezones": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/@nextcloud/timezones/-/timezones-1.0.0.tgz",
-      "integrity": "sha512-9b7Wms2mzB4RAltf8s9dY40PcU5ova5QjQJw1Gty35e54alKyx33BqUOy4gEbkzmYSrW4aZcLcMrOO5Bj2eIzg==",
-      "license": "AGPL-3.0-or-later",
-      "dependencies": {
-        "ical.js": "^2.1.0"
-      },
-      "engines": {
-        "node": "^20 || ^22"
-      }
-    },
     "node_modules/@nextcloud/typings": {
       "version": "1.9.1",
       "resolved": "https://registry.npmjs.org/@nextcloud/typings/-/typings-1.9.1.tgz",
@@ -13457,12 +13444,6 @@
       "dev": true,
       "license": "BSD-3-Clause"
     },
-    "node_modules/ical.js": {
-      "version": "2.2.1",
-      "resolved": "https://registry.npmjs.org/ical.js/-/ical.js-2.2.1.tgz",
-      "integrity": "sha512-yK/UlPbEs316igb/tjRgbFA8ZV75rCsBJp/hWOatpyaPNlgw0dGDmU+FoicOcwX4xXkeXOkYiOmCqNPFpNPkQg==",
-      "license": "MPL-2.0"
-    },
     "node_modules/iconv-lite": {
       "version": "0.6.3",
       "resolved": "https://registry.npmjs.org/iconv-lite/-/iconv-lite-0.6.3.tgz",
diff --git a/package.json b/package.json
index 138da927f8..87f25b25b0 100644
--- a/package.json
+++ b/package.json
@@ -87,7 +87,6 @@
     "@nextcloud/logger": "^3.0.2",
     "@nextcloud/router": "^3.0.1",
     "@nextcloud/sharing": "^0.3.0",
-    "@nextcloud/timezones": "^1.0.0",
     "@vuepic/vue-datepicker": "^11.0.2",
     "@vueuse/components": "^13.9.0",
     "@vueuse/core": "^13.9.0",
diff --git a/src/components/NcTimezonePicker/NcTimezonePicker.vue b/src/components/NcTimezonePicker/NcTimezonePicker.vue
index 02d512f8ed..2106fc2504 100644
--- a/src/components/NcTimezonePicker/NcTimezonePicker.vue
+++ b/src/components/NcTimezonePicker/NcTimezonePicker.vue
@@ -16,7 +16,7 @@
 export default {
 	data() {
 		return {
-			tz: 'Hawaiian Standard Time',
+			tz: 'Europe/Berlin',
 		}
 	},
 }
@@ -25,21 +25,27 @@ export default {
 </docs>
 
 <script setup lang="ts">
-import type {
-	IContinent,
-	IRegion,
-	ITimezone,
-} from '@nextcloud/timezones'
-
-import {
-	getReadableTimezoneName,
-	getSortedTimezoneList,
-} from '@nextcloud/timezones'
+import { getCanonicalLocale } from '@nextcloud/l10n'
 import { computed } from 'vue'
+import NcSelect from '../NcSelect/NcSelect.vue'
 import { t } from '../../l10n.ts'
 import { createElementId } from '../../utils/createElementId.ts'
-import NcSelect from '../NcSelect/index.js'
-import getTimezoneManager from './timezoneDataProviderService.js'
+import { getTimezones } from './timezoneUtils.ts'
+
+export type ITimezone = {
+	/**
+	 * Time zone ID in IANA format, e.g. "Europe/Berlin", or "floating" for a time independent of timezone, or a custom timezone ID
+	 */
+	timezoneId: string
+	/**
+	 * Localized label of the timezone, e.g. "Central European Standard Time"
+	 */
+	label: string
+	/**
+	 * Continent the timezone if any, e.g. "Europe" (not localized)
+	 */
+	continent: string
+}
 
 /**
  * The selected timezone.
@@ -63,109 +69,113 @@ const props = withDefaults(defineProps<{
 	uid: createElementId(),
 })
 
-const selectedTimezone = computed({
-	set(timezone: IRegion) {
-		modelValue.value = timezone.timezoneId
-	},
-	get(): IRegion {
-		for (const additionalTimezone of props.additionalTimezones) {
-			if (additionalTimezone.timezoneId === modelValue.value) {
-				return {
-					cities: [],
-					...additionalTimezone,
-				}
-			}
-		}
-
-		return {
-			label: getReadableTimezoneName(modelValue.value),
-			timezoneId: modelValue.value,
-			cities: [],
-		}
-	},
+const formattedAdditionalTimezones = computed(() => {
+	return props.additionalTimezones.map(({ timezoneId, label }) => ({
+		timezoneId,
+		label,
+		offset: 0,
+		localeOffset: '',
+		time: '',
+	}))
 })
 
 const options = computed(() => {
-	const timezoneManager = getTimezoneManager()
-	const timezoneList: IContinent[] = getSortedTimezoneList(
-		timezoneManager.listAllTimezones(),
-		props.additionalTimezones,
-		t('Global'), // TRANSLATORS: This refers to global timezones in the timezone picker
-	)
-	/**
-	 * Since NcSelect does not support groups,
-	 * we create an object with the grouped timezones and continent labels.
-	 *
-	 * NOTE for now we are removing the grouping from the fields to fix an accessibility issue
-	 * in the future, other options can be introduced to better display the different areas
-	 */
-	const timezonesGrouped: IRegion[] = []
-	for (const group of Object.values(timezoneList)) {
-		// Add an entry as group label
-		// const continent = `tz-group__${group.continent}`
-		// timezonesGrouped.push({
-		// label: group.continent,
-		// continent,
-		// timezoneId: continent,
-		// regions: group.regions,
-		// })
-		timezonesGrouped.push(...group.regions)
-	}
-	return timezonesGrouped
+	const timezones = getTimezones()
+	const now = new Date()
+	console.time('Adding current time to timezones')
+	const result = timezones.map((option) => ({
+		...option,
+		time: now.toLocaleString(getCanonicalLocale(), { timeZone: option.timezoneId, hour: '2-digit', minute: '2-digit' }),
+	}))
+	console.timeEnd('Adding current time to timezones')
+	result.unshift(...formattedAdditionalTimezones.value)
+	return result
 })
 
 /**
- * Returns whether this is a continent label,
- * or an actual timezone. Continent labels are not selectable.
- *
- * @param option The option
- */
-function isSelectable(option: IRegion): boolean {
-	return !option.timezoneId.startsWith('tz-group__')
-}
-
-/**
- * Function to filter the timezone list.
- * We search in the timezoneId, so both continent and region names can be matched.
+ * NcSelect's filterBy prop to search timezone by any option property
  *
  * @param option - The timezone option
  * @param label - The label of the timezone
  * @param search - The search string
  */
-function filterBy(option: IContinent | IRegion, label: string, search: string): boolean {
-	// We split the search term in case one searches "<continent> <region>".
-	const terms = search.trim().split(' ')
-
-	// For the continent labels, we have to check if one region matches every search term.
-	if ('continent' in option) {
-		return option.regions.some((region) => {
-			return matchTimezoneId(region.timezoneId, terms)
-		})
-	}
-
-	// For a region, every search term must be found.
-	return matchTimezoneId(option.timezoneId, terms)
+function filterBy(option: ITimezone, label: string, search: string): boolean {
+	const terms = search.trim().split(/\s+/)
+	const values = Object.values(option)
+	return terms.every((term) => {
+		return values.some((value) => value.toLowerCase().includes(term.toLowerCase()))
+	})
 }
 
-/**
- * @param timezoneId - The timezone id to check
- * @param terms - Terms to validate
- */
-function matchTimezoneId(timezoneId: string, terms: string[]): boolean {
-	return terms.every((term) => timezoneId.toLowerCase().includes(term.toLowerCase()))
-}
+// Getting all the timezones with the current user language takes around 250ms on the first run
+// To prevent the lag on the first open, calculating them in an idle callback
+// TODO: maybe it is better to load it on open? More laggy, but doesn't load the page when not needed
+requestIdleCallback(() => {
+	getTimezones()
+})
 </script>
 
 <template>
 	<NcSelect
-		v-model="selectedTimezone"
+		v-model="modelValue"
 		:aria-label-combobox="t('Search for timezone')"
 		:clearable="false"
 		:filter-by
 		:multiple="false"
 		:options
 		:placeholder="t('Type to search time zone')"
-		:selectable="isSelectable"
 		:uid
-		label="label" />
+		:reduce="(option) => option.timezoneId"
+		label="label">
+		<template #option="option">
+			<span :class="$style.timezoneOption">
+				<span :class="$style.timezoneOption__row">
+					<span>{{ option.label }}</span>
+					<span :class="$style.timezoneOption__time">{{ option.time }}</span>
+				</span>
+				<span :class="[$style.timezoneOption__row, $style.timezoneOption__subline]">
+					<span :class="$style.timezoneOption__id">{{ option.timezoneId }}</span>
+					<span :class="$style.timezoneOption__offset">{{ option.localeOffset }}</span>
+				</span>
+			</span>
+		</template>
+	</NcSelect>
 </template>
+
+<style lang="scss" module>
+/* Dirty hack to override the padding of vue-select options */
+li:has(> .timezoneOption) {
+	padding: calc(1 * var(--default-grid-baseline));
+}
+
+.timezoneOption {
+	display: flex;
+	flex-direction: column;
+	white-space: break-spaces;
+}
+
+.timezoneOption__row {
+	display: flex;
+	justify-content: space-between;
+	gap: calc(1 * var(--default-grid-baseline));
+}
+
+.timezoneOption__subline {
+	color: var(--color-text-maxcontrast);
+	font-size: var(--font-size-small, 13px);
+}
+
+.timezoneOption__offset,
+.timezoneOption__time {
+	white-space: nowrap;
+}
+
+.timezoneOption__time {
+	font-size: var(--font-size-small, 13px);
+}
+
+.timezoneOption__id {
+	/* Timezone ID can be long without spaces, like America/North_Dakota/New_Salem */
+	overflow-wrap: anywhere;
+}
+</style>
diff --git a/src/components/NcTimezonePicker/timezoneDataProviderService.ts b/src/components/NcTimezonePicker/timezoneDataProviderService.ts
deleted file mode 100644
index 923391e358..0000000000
--- a/src/components/NcTimezonePicker/timezoneDataProviderService.ts
+++ /dev/null
@@ -1,22 +0,0 @@
-/**
- * SPDX-FileCopyrightText: 2019 Nextcloud GmbH and Nextcloud contributors
- * SPDX-License-Identifier: AGPL-3.0-or-later
- */
-
-import { getTimezoneManager } from '@nextcloud/timezones'
-
-const timezoneManager = getTimezoneManager()
-let initialized = false
-
-/**
- * Gets the timezone-manager
- * initializes it if necessary
- */
-export default function() {
-	if (!initialized) {
-		timezoneManager.registerDefaultTimezones()
-		initialized = true
-	}
-
-	return timezoneManager
-}
diff --git a/src/components/NcTimezonePicker/timezoneUtils.ts b/src/components/NcTimezonePicker/timezoneUtils.ts
new file mode 100644
index 0000000000..1d72bccbdb
--- /dev/null
+++ b/src/components/NcTimezonePicker/timezoneUtils.ts
@@ -0,0 +1,63 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import { getLanguage } from '@nextcloud/l10n'
+import { memoize } from '../../utils/utils.ts'
+
+const now = new Date()
+
+/**
+ * Convert timezone ID in IANA format (e.g. "Europe/Berlin") to specified format via Intl.DateTimeFormat
+ *
+ * @param timeZone - IANA timezone ID (e.g. "Europe/Berlin")
+ * @param timeZoneName - Intl.DateTimeFormatOptions['timeZoneName']
+ * @param lang - Language code (e.g. 'en'), defaults to the current user's language
+ */
+export function formatTimezone(timeZone: string, timeZoneName: NonNullable<Intl.DateTimeFormatOptions['timeZoneName']>, lang: string = getLanguage()): string | undefined {
+	return new Intl.DateTimeFormat(lang, { timeZone, timeZoneName })
+		.formatToParts(now)
+		.find((part) => part.type === 'timeZoneName')
+		?.value
+}
+
+/**
+ * Get offset in ms for a given timezone ID in IANA format (e.g. "Europe/Berlin")
+ *
+ * @param timeZone - IANA timezone ID (e.g. "Europe/Berlin")
+ * @return - Offset in milliseconds (e.g. 3600000 for GMT+01:00)
+ */
+const getTimezoneOffset = memoize((timeZone: string): number => {
+	// 'en-US' gives predictable GMT+00:00 or GMT+00:00:00 format
+	const gmt = formatTimezone(timeZone, 'longOffset', 'en-US')
+	const [isMatched, sign, h = '0', m = '0', s = '0'] = gmt?.match(/GMT([+-])(\d+):(\d+)(?::(\d+))?/) ?? []
+	if (!isMatched) {
+		return 0
+	}
+	return (sign === '+' ? 1 : -1) * (parseInt(h) * 3600 + parseInt(m) * 60 + parseInt(s)) * 1000
+})
+
+/**
+ * Get a list of supported IANA timezone IDs (e.g. "Europe/Berlin") with human-readable labels,
+ * excluding Etc/* administrative zones not used by users (see: https://en.wikipedia.org/wiki/Tz_database#Areas)
+ */
+export const getTimezones = memoize(() => {
+	const zones = Intl.supportedValuesOf('timeZone')
+		.filter((tz) => !tz.startsWith('Etc/'))
+	console.time('Adding formatted timezone labels')
+	const result = zones.map((timezoneId) => ({
+		timezoneId,
+		label: formatTimezone(timezoneId, 'shortGeneric'), // Alternative: longGeneric, but too long our select design..
+		offset: getTimezoneOffset(timezoneId),
+		localeOffset: formatTimezone(timezoneId, 'shortOffset'),
+	}))
+	console.timeEnd('Adding formatted timezone labels')
+	// Sort by offset first, then by name
+	result.sort((a, b) => a.offset - b.offset || a.timezoneId.localeCompare(b.timezoneId))
+	return result
+})
+
+// See:
+// https://play.vuejs.org/#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
+// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat
diff --git a/src/utils/utils.ts b/src/utils/utils.ts
new file mode 100644
index 0000000000..c9779b4771
--- /dev/null
+++ b/src/utils/utils.ts
@@ -0,0 +1,47 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+/* eslint-disable @typescript-eslint/no-explicit-any */
+
+export function once<F extends () => any>(func: F): F
+export function once<F extends (...args: any[]) => void>(func: F): F
+/**
+ * Singletone function decorator
+ *
+ * @param func - Function
+ */
+export function once<F extends(() => any) | ((...args: any[]) => void)>(func: F): F {
+	let wasCalled = false
+	let result: ReturnType<F>
+
+	return ((...args: Parameters<F>): ReturnType<F> => {
+		if (!wasCalled) {
+			wasCalled = true
+			result = func(...args)
+		}
+		return result
+	}) as F
+}
+
+/**
+ * Memoization function decorator
+ *
+ * @param func - Function to memoize with a single argument
+ */
+export function memoize<F extends(arg: any) => any>(func: F): F {
+	const cache = new Map<Parameters<F>[0], ReturnType<F>>()
+
+	return ((arg: Parameters<F>[0]): ReturnType<F> => {
+		if (cache.has(arg)) {
+			return cache.get(arg)!
+		}
+
+		const result = func(arg)
+		cache.set(arg, result)
+		return result
+	}) as F
+}
+
+/* eslint-enable @typescript-eslint/no-explicit-any */