diff --git a/api/js/etemplate/et2_widget_countdown.js b/api/js/etemplate/et2_widget_countdown.js
index 5b9c1498f8..1b3a7452dd 100644
--- a/api/js/etemplate/et2_widget_countdown.js
+++ b/api/js/etemplate/et2_widget_countdown.js
@@ -34,7 +34,9 @@ var et2_core_valueWidget_1 = require("./et2_core_valueWidget");
 /**
  * Class which implements the "countdown" XET-Tag
  *
- * Value for countdown is the expiry date of the counter.
+ * Value for countdown is the expiry date of the counter or a numeric timeout in seconds.
+ *
+ * The timeout has the benefit, that it does not depend on the correct set time and timezone of the browser / computer of the user.
  */
 var et2_countdown = /** @class */ (function (_super) {
     __extends(et2_countdown, _super);
@@ -65,11 +67,21 @@ var et2_countdown = /** @class */ (function (_super) {
         // create a date widget
         _this.time = et2_core_widget_1.et2_createWidget('date-time', {});
         _this.setDOMNode(_this.container[0]);
+        _this.offset = (new Date).getTimezoneOffset();
         return _this;
     }
     et2_countdown.prototype.set_value = function (_time) {
         if (_time == "")
             return;
+        if (!isNaN(_time)) {
+            var t = new Date();
+            t.setSeconds(t.getSeconds() + parseInt(_time));
+            _time = t;
+            this.offset = 0;
+        }
+        else {
+            this.offset = (new Date).getTimezoneOffset();
+        }
         this.time.set_value(_time);
         var self = this;
         this.timer = setInterval(function () {
@@ -82,7 +94,7 @@ var et2_countdown = /** @class */ (function (_super) {
     };
     et2_countdown.prototype._updateTimer = function () {
         var tempDate = new Date();
-        var now = new Date(tempDate.getFullYear(), tempDate.getMonth(), tempDate.getDate(), tempDate.getHours(), tempDate.getMinutes() - tempDate.getTimezoneOffset(), tempDate.getSeconds());
+        var now = new Date(tempDate.getFullYear(), tempDate.getMonth(), tempDate.getDate(), tempDate.getHours(), tempDate.getMinutes() - this.offset, tempDate.getSeconds());
         var time = new Date(this.time.getValue());
         var distance = time.getTime() - now.getTime();
         if (distance < 0)
diff --git a/api/js/etemplate/et2_widget_countdown.ts b/api/js/etemplate/et2_widget_countdown.ts
index c04b9595b6..eca57c2c8e 100644
--- a/api/js/etemplate/et2_widget_countdown.ts
+++ b/api/js/etemplate/et2_widget_countdown.ts
@@ -23,7 +23,9 @@ import {et2_valueWidget} from "./et2_core_valueWidget";
 /**
  * Class which implements the "countdown" XET-Tag
  *
- * Value for countdown is the expiry date of the counter.
+ * Value for countdown is the expiry date of the counter or a numeric timeout in seconds.
+ *
+ * The timeout has the benefit, that it does not depend on the correct set time and timezone of the browser / computer of the user.
  */
 export class et2_countdown extends et2_valueWidget {
 	static readonly _attributes: any = {
@@ -57,7 +59,6 @@ export class et2_countdown extends et2_valueWidget {
 			default: "",
 			description: "Defines a callback to gets called at alarm - timer. This only will work if there's an alarm set."
 		}
-
 	};
 
 	private time : et2_date;
@@ -68,6 +69,7 @@ export class et2_countdown extends et2_valueWidget {
 	private hours : JQuery = null;
 	private minutes : JQuery = null;
 	private seconds : JQuery = null;
+	private offset;
 
 	/**
 	 * Constructor
@@ -90,11 +92,23 @@ export class et2_countdown extends et2_valueWidget {
 		// create a date widget
 		this.time = <et2_date> et2_createWidget('date-time', {});
 		this.setDOMNode(this.container[0]);
+		this.offset = (new Date).getTimezoneOffset();
 	}
 
 	public set_value(_time)
 	{
 		if (_time == "") return;
+		if (!isNaN(_time))
+		{
+			let t = new Date();
+			t.setSeconds(t.getSeconds()+parseInt(_time));
+			_time = t;
+			this.offset = 0;
+		}
+		else
+		{
+			this.offset = (new Date).getTimezoneOffset();
+		}
 		this.time.set_value(_time);
 		let self = this;
 		this.timer = setInterval(function(){
@@ -114,7 +128,7 @@ export class et2_countdown extends et2_valueWidget {
 			tempDate.getMonth(),
 			tempDate.getDate(),
 			tempDate.getHours(),
-			tempDate.getMinutes()-tempDate.getTimezoneOffset(),
+			tempDate.getMinutes()-this.offset,
 			tempDate.getSeconds()
 		);
 
diff --git a/api/src/Etemplate/Widget/Countdown.php b/api/src/Etemplate/Widget/Countdown.php
new file mode 100644
index 0000000000..0c82fb937a
--- /dev/null
+++ b/api/src/Etemplate/Widget/Countdown.php
@@ -0,0 +1,40 @@
+<?php
+/**
+ * EGroupware - eTemplate serverside countdown widget
+ *
+ * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
+ * @package api
+ * @subpackage etemplate
+ * @link http://www.egroupware.org
+ * @author Ralf Becker <rb@egroupware.org>
+ * @copyright 2021 by rb@egroupware.org
+ */
+
+namespace EGroupware\Api\Etemplate\Widget;
+
+use EGroupware\Api;
+
+/**
+ * eTemplate countdown widget
+ *
+ */
+class Countdown extends Api\Etemplate\Widget
+{
+	/**
+	 * Convert end-datetime of countdown into a difference in seconds to avoid errors due to wrong time&timezone on client
+	 *
+	 * @param string $cname
+	 * @param array $expand values for keys 'c', 'row', 'c_', 'row_', 'cont'
+	 */
+	public function beforeSendToClient($cname, array $expand=null)
+	{
+		$form_name = self::form_name($cname, $this->id, $expand);
+		$value =& self::get_array(self::$request->content, $form_name, false, true);
+
+		if ($value)
+		{
+			$value = Api\DateTime::to($value, 'utc') - Api\DateTime::to('now', 'utc');
+		}
+	}
+}
+\EGroupware\Api\Etemplate\Widget::registerWidget(Countdown::class, 'countdown');
\ No newline at end of file
diff --git a/api/src/Etemplate/Widget/Date.php b/api/src/Etemplate/Widget/Date.php
index 0bca6e1a28..f6895765f6 100644
--- a/api/src/Etemplate/Widget/Date.php
+++ b/api/src/Etemplate/Widget/Date.php
@@ -256,4 +256,4 @@ class Date extends Transformer
 		}
 	}
 }
-\EGroupware\Api\Etemplate\Widget::registerWidget(__NAMESPACE__.'\\Date', array('time_or_date', 'countdown'));
\ No newline at end of file
+\EGroupware\Api\Etemplate\Widget::registerWidget(__NAMESPACE__.'\\Date', array('time_or_date'));
\ No newline at end of file