diff --git a/completion/classes/form/form_trait.php b/completion/classes/form/form_trait.php
index 166f010d23c..e539767d74c 100644
--- a/completion/classes/form/form_trait.php
+++ b/completion/classes/form/form_trait.php
@@ -207,8 +207,9 @@ trait form_trait {
         $completionexpectedel = 'completionexpected' . $suffix;
         $mform->addElement('date_time_selector', $completionexpectedel, get_string('completionexpected', 'completion'),
                 ['optional' => true]);
-        $mform->addHelpButton($completionexpectedel, 'completionexpected', 'completion');
-        $mform->hideIf($completionexpectedel, $completionel, 'eq', COMPLETION_TRACKING_NONE);
+        $a = get_string('pluginname', $modname);
+        $mform->addHelpButton($completionexpectedel, 'completionexpected', 'completion', '', false, $a);
+        $mform->hideIf($completionexpectedel, 'completion', 'eq', COMPLETION_TRACKING_NONE);
     }
 
     /**
diff --git a/lang/en/completion.php b/lang/en/completion.php
index 7242f68a62d..3e8d7bb3b74 100644
--- a/lang/en/completion.php
+++ b/lang/en/completion.php
@@ -91,8 +91,8 @@ $string['completionactivitydefault'] = 'Use activity default';
 $string['completiondefault'] = 'Default completion tracking';
 $string['completiondisabled'] = 'Disabled, not shown in activity settings';
 $string['completionenabled'] = 'Enabled, control via completion and activity settings';
-$string['completionexpected'] = 'Expect completed on';
-$string['completionexpected_help'] = 'This setting specifies the date when the activity is expected to be completed. When the date is upcoming, the activity is listed in the Timeline block on the Dashboard.';
+$string['completionexpected'] = 'Set reminder in Timeline';
+$string['completionexpected_help'] = 'This allows you to set a reminder for students to work on this activity. It will appear on the Timeline block in their Dashboard as "{$a} requires action"';
 $string['completionexpecteddesc'] = 'Completion expected on {$a}';
 $string['completionexpectedfor'] = '{$a->instancename} should be completed';
 $string['completionicons'] = 'Completion tick boxes';
diff --git a/lib/formslib.php b/lib/formslib.php
index bba17179d20..2eb2f78bd0d 100644
--- a/lib/formslib.php
+++ b/lib/formslib.php
@@ -2354,12 +2354,21 @@ class MoodleQuickForm extends HTML_QuickForm_DHTMLRulesTableless {
      * @param string $component component name to look the help string in
      * @param string $linktext optional text to display next to the icon
      * @param bool $suppresscheck set to true if the element may not exist
+     * @param string|object|array|int $a An object, string or number that can be used
+     *      within translation strings
      */
-    function addHelpButton($elementname, $identifier, $component = 'moodle', $linktext = '', $suppresscheck = false) {
+    public function addHelpButton(
+        $elementname,
+        $identifier,
+        $component = 'moodle',
+        $linktext = '',
+        $suppresscheck = false,
+        $a = null
+    ) {
         global $OUTPUT;
         if (array_key_exists($elementname, $this->_elementIndex)) {
             $element = $this->_elements[$this->_elementIndex[$elementname]];
-            $element->_helpbutton = $OUTPUT->help_icon($identifier, $component, $linktext);
+            $element->_helpbutton = $OUTPUT->help_icon($identifier, $component, $linktext, $a);
         } else if (!$suppresscheck) {
             debugging(get_string('nonexistentformelements', 'form', $elementname));
         }
diff --git a/lib/outputcomponents.php b/lib/outputcomponents.php
index a9090f21ab9..73480ad18e2 100644
--- a/lib/outputcomponents.php
+++ b/lib/outputcomponents.php
@@ -456,6 +456,11 @@ class help_icon implements renderable, templatable {
      */
     public $linktext = null;
 
+    /**
+     * @var mixed An object, string or number that can be used within translation strings
+     */
+    public $a = null;
+
     /**
      * Constructor
      *
@@ -463,10 +468,13 @@ class help_icon implements renderable, templatable {
      *  string with _help suffix is used for the actual help text.
      *  string with _link suffix is used to create a link to further info (if it exists)
      * @param string $component
+     * @param string|object|array|int $a An object, string or number that can be used
+     *      within translation strings
      */
-    public function __construct($identifier, $component) {
+    public function __construct($identifier, $component, $a = null) {
         $this->identifier = $identifier;
         $this->component  = $component;
+        $this->a = $a;
     }
 
     /**
@@ -491,7 +499,7 @@ class help_icon implements renderable, templatable {
     public function export_for_template(renderer_base $output) {
         global $CFG;
 
-        $title = get_string($this->identifier, $this->component);
+        $title = get_string($this->identifier, $this->component, $this->a);
 
         if (empty($this->linktext)) {
             $alt = get_string('helpprefix2', '', trim($title, ". \t"));
@@ -499,7 +507,7 @@ class help_icon implements renderable, templatable {
             $alt = get_string('helpwiththis');
         }
 
-        $data = get_formatted_help_string($this->identifier, $this->component, false);
+        $data = get_formatted_help_string($this->identifier, $this->component, false, $this->a);
 
         $data->alt = $alt;
         $data->icon = (new pix_icon('help', $alt, 'core', ['class' => 'iconhelp']))->export_for_template($output);
diff --git a/lib/outputrenderers.php b/lib/outputrenderers.php
index b1cbf57c290..59bfce5ce7d 100644
--- a/lib/outputrenderers.php
+++ b/lib/outputrenderers.php
@@ -2521,13 +2521,15 @@ class core_renderer extends renderer_base {
      * @param string $identifier The keyword that defines a help page
      * @param string $component component name
      * @param string|bool $linktext true means use $title as link text, string means link text value
+     * @param string|object|array|int $a An object, string or number that can be used
+     *      within translation strings
      * @return string HTML fragment
      */
-    public function help_icon($identifier, $component = 'moodle', $linktext = '') {
-        $icon = new help_icon($identifier, $component);
+    public function help_icon($identifier, $component = 'moodle', $linktext = '', $a = null) {
+        $icon = new help_icon($identifier, $component, $a);
         $icon->diag_strings();
         if ($linktext === true) {
-            $icon->linktext = get_string($icon->identifier, $icon->component);
+            $icon->linktext = get_string($icon->identifier, $icon->component, $a);
         } else if (!empty($linktext)) {
             $icon->linktext = $linktext;
         }
diff --git a/lib/upgrade.txt b/lib/upgrade.txt
index b826aba2190..387c7450711 100644
--- a/lib/upgrade.txt
+++ b/lib/upgrade.txt
@@ -79,6 +79,8 @@ information provided here is intended especially for developers.
 * The behat step I choose "WHATEVER" in the open action menu is now compatible with action menus subpanels
   using the ">" symbol to suparate the item link text and subitem one. For example:
   - I choose "Group mode > Visible groups" in the open action menu
+* addHelpButton() function has a new optional $a parameter to allow variables with translation strings.
+* help_icon constructor has a new optional $a parameter to allow variables with translation strings.
 
 === 4.2 ===