diff --git a/api/js/jsapi/egw_timer.js b/api/js/jsapi/egw_timer.js
index 5734364055..c3f3025ff8 100644
--- a/api/js/jsapi/egw_timer.js
+++ b/api/js/jsapi/egw_timer.js
@@ -93,9 +93,10 @@ egw.extend('timer', egw.MODULE_GLOBAL, function()
 	 *
 	 * @param {string} _action
 	 * @param {string} _time
+	 * @param {string} _app_id
 	 * @throws string error-message
 	 */
-	function timerAction(_action, _time)
+	function timerAction(_action, _time, _app_id)
 	{
 		switch(_action)
 		{
@@ -126,9 +127,14 @@ egw.extend('timer', egw.MODULE_GLOBAL, function()
 				stopTimer(specific, false, _time);
 				break;
 		}
+		// set _app_id on timer, if specified
+		if (_app_id && _action.substring(0, 8) === 'specific')
+		{
+			specific.app_id = _app_id;
+		}
 		// persist state
 		egw.request('timesheet.EGroupware\\Timesheet\\Events.ajax_event', [getState(_action, _time)]).then((tse_id) => {
-			if (_action.substring(8) === 'specific')
+			if (_action.substring(0, 8) === 'specific')
 			{
 				specific.id = tse_id;
 			}
@@ -247,9 +253,8 @@ egw.extend('timer', egw.MODULE_GLOBAL, function()
 	 * @param object _timer
 	 * @param string|Date|undefined _start to initialise with time different from current time
 	 * @param number|undefined _offset to set an offset
-	 * @param string|undefined _app_id
 	 */
-	function startTimer(_timer, _start, _offset, _app_id)
+	function startTimer(_timer, _start, _offset)
 	{
 		// update _timer state object
 		if (_start)
@@ -266,7 +271,7 @@ egw.extend('timer', egw.MODULE_GLOBAL, function()
 		}
 		_timer.offset = 0;	// it's now set in start-time
 		_timer.paused = false;
-		_timer.app_id = _app_id;
+		_timer.app_id = undefined;
 
 		// update now
 		update();
@@ -350,7 +355,7 @@ egw.extend('timer', egw.MODULE_GLOBAL, function()
 						{
 							if (specific.paused)
 							{
-								startTimer(specific, undefined, undefined, _senders[0].id);
+								timerAction('specific-start', undefined, _senders[0].id);
 							}
 							else
 							{
@@ -364,7 +369,7 @@ egw.extend('timer', egw.MODULE_GLOBAL, function()
 					Et2Dialog.BUTTONS_OK_CANCEL, Et2Dialog.QUESTION_MESSAGE, undefined, egw);
 				return;
 			}
-			startTimer(specific, undefined, undefined, _senders[0].id);
+			timerAction('specific-start', undefined, _senders[0].id);
 		},
 
 		/**
diff --git a/calendar/inc/class.calendar_uilist.inc.php b/calendar/inc/class.calendar_uilist.inc.php
index a7788c1914..1758a90871 100644
--- a/calendar/inc/class.calendar_uilist.inc.php
+++ b/calendar/inc/class.calendar_uilist.inc.php
@@ -1105,6 +1105,27 @@ class calendar_uilist extends calendar_ui
 				'allowOnMultiple' => 'only',
 				'hideOnDisabled' => true,	// show only one timesheet action in context menu
 			);
+			// if specific timer is NOT disabled, allow to book further time on existing sheets
+			$config = Api\Config::read('timesheet');
+			if (!in_array('specific', $config['disable_timer'] ?? []))
+			{
+				$actions['timesheet'] = [
+					'icon' => 'timesheet/navbar',
+					'caption' => 'Timesheet',
+					'group' => $group,
+					'children' => array_map(static function($child) { unset($child['group']); return $child; }, [
+						'timesheet-interactive' => ['caption' => 'Add']+$actions['timesheet'],
+						'timesheet-add' => ['caption' => 'Add']+$actions['timesheet-add'],
+						'timer' => [
+							'icon' => 'timesheet/navbar',
+							'caption' => 'Start timer',
+							'onExecute' => 'javaScript:app.timesheet.egw.start_timer',
+							'allowOnMultiple' => false,
+						],
+					]),
+				];
+				unset($actions['timesheet-add']);
+			}
 		}
 		$actions['ical'] = array(
 			'icon' => 'ical',
@@ -1140,4 +1161,4 @@ class calendar_uilist extends calendar_ui
 		//_debug_array($actions);
 		return $actions;
 	}
-}
+}
\ No newline at end of file
diff --git a/infolog/inc/class.infolog_ui.inc.php b/infolog/inc/class.infolog_ui.inc.php
index fd60d361d9..2ba951cb6e 100644
--- a/infolog/inc/class.infolog_ui.inc.php
+++ b/infolog/inc/class.infolog_ui.inc.php
@@ -1294,6 +1294,17 @@ class infolog_ui
 					)
 				)
 			);
+			// if specific timer is NOT disabled, allow to book further time on existing sheets
+			$config = Api\Config::read('timesheet');
+			if (!in_array('specific', $config['disable_timer'] ?? []))
+			{
+				$actions['timesheet']['children']['timer'] = array(
+					'icon' => 'timesheet/navbar',
+					'caption' => 'Start timer',
+					'onExecute' => 'javaScript:app.timesheet.egw.start_timer',
+					'allowOnMultiple' => false,
+				);
+			}
 		}
 		if ($GLOBALS['egw_info']['user']['apps']['tracker'])
 		{
@@ -2723,4 +2734,4 @@ class infolog_ui
 		}
 		return $fields;
 	}
-}
+}
\ No newline at end of file
diff --git a/timesheet/inc/class.timesheet_ui.inc.php b/timesheet/inc/class.timesheet_ui.inc.php
index bdaff99e3f..61fdff8e9f 100644
--- a/timesheet/inc/class.timesheet_ui.inc.php
+++ b/timesheet/inc/class.timesheet_ui.inc.php
@@ -112,26 +112,11 @@ class timesheet_ui extends timesheet_bo
 				{
 					if (!empty($event['tse_app']) && $event['tse_app'] !== TIMESHEET_APP && !empty($event['tse_app_id']))
 					{
-						// existing timesheets can be directly linked (takes care to not link multiple times)
-						if ($this->data['ts_id'])
+						if (!isset($this->data['link_to']['to_id']))
 						{
-							Api\Link::link(TIMESHEET_APP, $this->data['ts_id'], $event['tse_app'], $event['tse_app_id']);
-						}
-						// new timesheets will be linked on saving (need to check to not add multiple times)
-						else
-						{
-							if (!isset($this->data['link_to']['to_id']))
-							{
-								$this->data['link_to']['to_id'] = [];
-							}
-							if (!in_array($app_id = [
-								'to_app' => $event['tse_app'],
-								'to_id'  => $event['tse_app_id'],
-							], $this->data['link_to']['to_id']))
-							{
-								$this->data['link_to']['to_id'][] = $app_id;
-							}
+							$this->data['link_to']['to_id'] = $this->data['ts_id'] ?? [];
 						}
+						Api\Link::link(TIMESHEET_APP, $this->data['link_to']['to_id'], $event['tse_app'], $event['tse_app_id']);
 					}
 				}
 			}
diff --git a/timesheet/lang/egw_de.lang b/timesheet/lang/egw_de.lang
index c9676952dd..853b42e768 100644
--- a/timesheet/lang/egw_de.lang
+++ b/timesheet/lang/egw_de.lang
@@ -130,7 +130,7 @@ show a quantity sum (eg. to sum up negative overtime)	admin	de	Zeige eine Mengen
 skip record	timesheet	de	Eintrag überspringen
 start	timesheet	de	Start
 start & stop timer	common	de	Zeitnehmer starten & stoppen
-start timer	timesheet	de	Zeitnehmer starten
+start timer	common	de	Zeitnehmer starten
 starttime	timesheet	de	Startzeit
 starttime has to be before endtime !!!	timesheet	de	Startzeit muss vor der Endzeit liegen !!!
 status	timesheet	de	Status
diff --git a/timesheet/lang/egw_en.lang b/timesheet/lang/egw_en.lang
index 78ec512d8b..673939e0e3 100644
--- a/timesheet/lang/egw_en.lang
+++ b/timesheet/lang/egw_en.lang
@@ -130,7 +130,7 @@ show a quantity sum (eg. to sum up negative overtime)	admin	en	Show a quantity s
 skip record	timesheet	en	Skip record
 start	timesheet	en	Start
 start & stop timer	common	en	Start & stop timer
-start timer	timesheet	en	Start timer
+start timer	common	en	Start timer
 starttime	timesheet	en	Start time
 starttime has to be before endtime !!!	timesheet	en	Start time has to be before endtime!
 status	timesheet	en	Status
diff --git a/timesheet/src/Events.php b/timesheet/src/Events.php
index e9766ad2d8..5c067cbbac 100644
--- a/timesheet/src/Events.php
+++ b/timesheet/src/Events.php
@@ -94,9 +94,9 @@ class Events extends Api\Storage\Base
 			($action === 'start' ? self::START : ($action === 'stop' ? self::STOP : self::PAUSE));
 
 		$app = $id = $ts_id = null;
-		if ($timer === 'specific' && !empty($state['app_id']))
+		if ($timer === 'specific' && !empty($state['specific']['app_id']))
 		{
-			list($app, $id) = explode('::', $state['app_id'], 2);
+			list($app, $id) = explode('::', $state['specific']['app_id'], 2);
 			if ($app === self::APP)
 			{
 				$ts_id = $id;
@@ -127,7 +127,8 @@ class Events extends Api\Storage\Base
 				Api\Json\Response::get()->message(lang('Error storing working time').': '.$e->getMessage(), 'error');
 			}
 		}
-		return $this->data['tse_id'];
+		// return (new) tse_id
+		Api\Json\Response::get()->data($this->data['tse_id']);
 	}
 
 	/**