diff --git a/README.md b/README.md
index 6772421..bc23cc4 100644
--- a/README.md
+++ b/README.md
@@ -2,9 +2,9 @@
 
 [简体中文](README_zh.md)
 
-OI Contest Schedule is a lightweight WordPress plugin that displays upcoming competitive programming contests in the WordPress dashboard or on any post or page.
+OI Contest Schedule is a lightweight WordPress plugin that displays currently running and upcoming competitive programming contests in the WordPress dashboard or on any post or page. Contests that have ended are not displayed.
 
-Contest data is provided by [OI-contest-fetch](https://github.com/hanyixuanten/OI-contest-fetch) and displayed in each visitor's device time zone.
+Contest data is provided by [OI-contest-fetch](https://github.com/hanyixuanten/OI-contest-fetch) and displayed in each visitor's client device time zone, not the time zone configured in WordPress. The schedule identifies the client time zone by its IANA name, such as `Asia/Shanghai`.
 
 ## Features
 
diff --git a/README_zh.md b/README_zh.md
index 7ab5f42..126e701 100644
--- a/README_zh.md
+++ b/README_zh.md
@@ -2,9 +2,9 @@
 
 [English](README.md)
 
-OI Contest Schedule 是一款轻量级 WordPress 插件，可在 WordPress 仪表盘、文章或页面中展示即将开始的程序设计竞赛。
+OI Contest Schedule 是一款轻量级 WordPress 插件，可在 WordPress 仪表盘、文章或页面中展示正在进行和即将开始的程序设计竞赛，不显示已结束的赛事。
 
-比赛数据由 [OI-contest-fetch](https://github.com/hanyixuanten/OI-contest-fetch) 提供，时间会根据访客设备的时区显示。
+比赛数据由 [OI-contest-fetch](https://github.com/hanyixuanten/OI-contest-fetch) 提供，时间会根据访客客户端设备的时区显示，而非 WordPress 中设置的站点时区。日程中会标明客户端时区的 IANA 名称，例如 `Asia/Shanghai`。
 
 ## 功能特性
 
diff --git a/assets/js/schedule.js b/assets/js/schedule.js
index 9ae9e69..f0fdbf4 100644
--- a/assets/js/schedule.js
+++ b/assets/js/schedule.js
@@ -29,6 +29,13 @@
 		} );
 	}
 
+	function updateTimeZones() {
+		var timeZone = Intl.DateTimeFormat().resolvedOptions().timeZone || 'UTC';
+		document.querySelectorAll( '[data-oics-time-zone]' ).forEach( function ( element ) {
+			element.textContent = timeZone;
+		} );
+	}
+
 	function countdownText( startTimestamp, endTimestamp ) {
 		var now = Date.now();
 		if ( endTimestamp * 1000 <= now ) {
@@ -57,8 +64,25 @@
 
 	function initialize() {
 		updateTimes();
+		updateTimeZones();
 		updateCountdowns();
 		window.setInterval( updateCountdowns, 1000 );
+
+		if ( 'MutationObserver' in window ) {
+			new MutationObserver( function ( mutations ) {
+				var hasAddedElements = mutations.some( function ( mutation ) {
+					return Array.prototype.some.call( mutation.addedNodes, function ( node ) {
+						return 1 === node.nodeType;
+					} );
+				} );
+
+				if ( hasAddedElements ) {
+					updateTimes();
+					updateTimeZones();
+					updateCountdowns();
+				}
+			} ).observe( document.body, { childList: true, subtree: true } );
+		}
 	}
 
 	if ( 'loading' === document.readyState ) {
diff --git a/includes/class-plugin.php b/includes/class-plugin.php
index a2595e3..8ea9ecd 100644
--- a/includes/class-plugin.php
+++ b/includes/class-plugin.php
@@ -29,7 +29,7 @@ final class OICS_Plugin {
 		wp_register_script(
 			'oics-schedule-editor',
 			OICS_URL . 'assets/js/schedule-editor.js',
-			array( 'wp-block-editor', 'wp-blocks', 'wp-components', 'wp-element', 'wp-server-side-render' ),
+			array( 'oics-schedule', 'wp-block-editor', 'wp-blocks', 'wp-components', 'wp-element', 'wp-server-side-render' ),
 			OICS_VERSION,
 			true
 		);
@@ -68,8 +68,11 @@ final class OICS_Plugin {
 	}
 
 	private function register_assets() {
-		wp_register_style( 'oics-schedule', OICS_URL . 'assets/css/schedule.css', array(), OICS_VERSION );
-		wp_register_script( 'oics-schedule', OICS_URL . 'assets/js/schedule.js', array(), OICS_VERSION, true );
+		$style_version  = OICS_VERSION . '.' . filemtime( OICS_PATH . 'assets/css/schedule.css' );
+		$script_version = OICS_VERSION . '.' . filemtime( OICS_PATH . 'assets/js/schedule.js' );
+
+		wp_register_style( 'oics-schedule', OICS_URL . 'assets/css/schedule.css', array(), $style_version );
+		wp_register_script( 'oics-schedule', OICS_URL . 'assets/js/schedule.js', array(), $script_version, true );
 		wp_localize_script(
 			'oics-schedule',
 			'oicsScheduleL10n',
diff --git a/includes/class-schedule-renderer.php b/includes/class-schedule-renderer.php
index c21110e..b32f30f 100644
--- a/includes/class-schedule-renderer.php
+++ b/includes/class-schedule-renderer.php
@@ -32,7 +32,8 @@ final class OICS_Schedule_Renderer {
 				<div>
 					<h2 class="oics-schedule__heading"><?php esc_html_e( 'Upcoming OI Contests', 'oi-contest-schedule' ); ?></h2>
 					<p class="oics-schedule__meta">
-						<?php esc_html_e( 'Times use your device time zone.', 'oi-contest-schedule' ); ?>
+						<?php esc_html_e( 'Device time zone', 'oi-contest-schedule' ); ?>:
+						<span data-oics-time-zone>UTC</span>
 					</p>
 				</div>
 				<span class="oics-schedule__count"><?php echo esc_html( sprintf( _n( '%d contest', '%d contests', count( $contests ), 'oi-contest-schedule' ), count( $contests ) ) ); ?></span>
diff --git a/languages/oi-contest-schedule-zh_CN.po b/languages/oi-contest-schedule-zh_CN.po
index 6234116..57abba5 100644
--- a/languages/oi-contest-schedule-zh_CN.po
+++ b/languages/oi-contest-schedule-zh_CN.po
@@ -64,8 +64,8 @@ msgstr "暂时无法加载赛事数据，请稍后再试。"
 msgid "No upcoming contests."
 msgstr "暂无即将开始的赛事。"
 
-msgid "Times use your device time zone."
-msgstr "时间按设备时区显示。"
+msgid "Device time zone"
+msgstr "设备时区"
 
 msgid "%d contest"
 msgid_plural "%d contests"
diff --git a/languages/oi-contest-schedule.pot b/languages/oi-contest-schedule.pot
index c088a1c..729be67 100644
--- a/languages/oi-contest-schedule.pot
+++ b/languages/oi-contest-schedule.pot
@@ -59,7 +59,7 @@ msgstr ""
 msgid "No upcoming contests."
 msgstr ""
 
-msgid "Times use your device time zone."
+msgid "Device time zone"
 msgstr ""
 
 msgid "%d contest"
diff --git a/readme.txt b/readme.txt
index ab5169c..2e071f1 100644
--- a/readme.txt
+++ b/readme.txt
@@ -8,11 +8,11 @@ Stable tag: 0.1.0
 License: GPL-3.0-only
 License URI: https://www.gnu.org/licenses/gpl-3.0.html
 
-Display upcoming OI and competitive programming contests in the WordPress dashboard or with an editor block.
+Display currently running and upcoming OI contests in the WordPress dashboard or with an editor block.
 
 == Description ==
 
-OI Contest Schedule displays upcoming competitive programming contests with local times and live countdowns.
+OI Contest Schedule displays currently running and upcoming competitive programming contests with local times and live countdowns. Contests that have ended are not displayed.
 
 The plugin adds an **Upcoming OI Contests** widget to the WordPress dashboard. To display the schedule on the front end, add the **OI Contest Schedule** block to a post or page.
 
@@ -20,7 +20,7 @@ Features include:
 
 * Upcoming and currently running contests ordered by start time.
 * Contest platform, title, start time, end time, and live countdown.
-* Dates formatted in each visitor's device time zone.
+* Dates formatted in each visitor's client device time zone, rather than the time zone configured in WordPress, and identified by its IANA name (for example, `Asia/Shanghai`).
 * Responsive and compact layouts.
 * A five-minute cache using the WordPress Transients API.
 * English and Simplified Chinese translations.
@@ -58,7 +58,7 @@ The plugin shows contests whose end time is still in the future, including conte
 
 = Which time zone is used? =
 
-Dates are formatted in the visitor's device time zone using the browser's internationalization API.
+Dates are formatted in the visitor's client device time zone using the browser's internationalization API. The time zone configured in the WordPress site settings is not used.
 
 = How often is the contest data refreshed? =