diff --git a/CRM/Activity/Form/Activity.php b/CRM/Activity/Form/Activity.php
index 24044465c56f..2e9ea0d3330e 100644
--- a/CRM/Activity/Form/Activity.php
+++ b/CRM/Activity/Form/Activity.php
@@ -163,9 +163,9 @@ public function setFields() {
         ),
       ),
       'duration' => array(
-        'type' => 'text',
+        'type' => 'number',
         'label' => ts('Duration'),
-        'attributes' => array('size' => 4, 'maxlength' => 8),
+        'attributes' => array('class' => 'four', 'min' => 1),
         'required' => FALSE,
       ),
       'location' => array(
@@ -207,6 +207,11 @@ public function setFields() {
           'api' => array('params' => array('is_deceased' => 0)),
         ),
       ),
+      'activity_date_time' => array(
+        'type' => 'datepicker',
+        'label' => ts('Date'),
+        'required' => TRUE,
+      ),
       'followup_assignee_contact_id' => array(
         'type' => 'entityRef',
         'label' => ts('Assigned to'),
@@ -559,16 +564,6 @@ public function setDefaultValues() {
     $defaults = $this->_values + CRM_Core_Form_RecurringEntity::setDefaultValues();
     // if we're editing...
     if (isset($this->_activityId)) {
-      if (empty($defaults['activity_date_time'])) {
-        list($defaults['activity_date_time'], $defaults['activity_date_time_time']) = CRM_Utils_Date::setDateDefaults(NULL, 'activityDateTime');
-      }
-      elseif ($this->_action & CRM_Core_Action::UPDATE) {
-        $this->assign('current_activity_date_time', $defaults['activity_date_time']);
-        list($defaults['activity_date_time'],
-          $defaults['activity_date_time_time']
-          ) = CRM_Utils_Date::setDateDefaults($defaults['activity_date_time'], 'activityDateTime');
-        list($defaults['repetition_start_date'], $defaults['repetition_start_date_time']) = CRM_Utils_Date::setDateDefaults($defaults['activity_date_time'], 'activityDateTime');
-      }
 
       if ($this->_context != 'standalone') {
         $this->assign('target_contact_value',
@@ -593,9 +588,10 @@ public function setDefaultValues() {
 
       $defaults['source_contact_id'] = $this->_sourceContactId;
       $defaults['target_contact_id'] = $this->_targetContactId;
+    }
 
-      list($defaults['activity_date_time'], $defaults['activity_date_time_time'])
-        = CRM_Utils_Date::setDateDefaults(NULL, 'activityDateTime');
+    if (empty($defaults['activity_date_time'])) {
+      $defaults['activity_date_time'] = date('Y-m-d H:i:s');
     }
 
     if ($this->_activityTypeId) {
@@ -759,7 +755,6 @@ public function buildQuickForm() {
     $this->addRule('duration',
       ts('Please enter the duration as number of minutes (integers only).'), 'positiveInteger'
     );
-    $this->addDateTime('activity_date_time', ts('Date'), TRUE, array('formatType' => 'activityDateTime'));
 
     // Add followup date.
     $this->addDateTime('followup_date', ts('in'), FALSE, array('formatType' => 'activityDateTime'));
@@ -948,9 +943,6 @@ public function postProcess($params = NULL) {
       );
     }
 
-    // store the date with proper format
-    $params['activity_date_time'] = CRM_Utils_Date::processDate($params['activity_date_time'], $params['activity_date_time_time']);
-
     // format params as arrays
     foreach (array('target', 'assignee', 'followup_assignee') as $name) {
       if (!empty($params["{$name}_contact_id"])) {
diff --git a/CRM/Case/Form/Activity.php b/CRM/Case/Form/Activity.php
index 580d4b58a4e5..a1f6809ec3b5 100644
--- a/CRM/Case/Form/Activity.php
+++ b/CRM/Case/Form/Activity.php
@@ -272,17 +272,14 @@ public function buildQuickForm() {
     $this->assign('urlPath', 'civicrm/case/activity');
 
     $encounterMediums = CRM_Case_PseudoConstant::encounterMedium();
-    // Fixme: what's the justification for this? It seems like it is just re-adding an option in case it is the default and disabled.
-    // Is that really a big problem?
-    if ($this->_activityTypeFile == 'OpenCase') {
-      $this->_encounterMedium = CRM_Core_DAO::getFieldValue('CRM_Activity_DAO_Activity', $this->_activityId,
-        'medium_id'
-      );
+    if ($this->_activityTypeFile == 'OpenCase' && $this->_action == CRM_Core_Action::UPDATE) {
+      $this->getElement('activity_date_time')->freeze();
+
+      // Fixme: what's the justification for this? It seems like it is just re-adding an option in case it is the default and disabled.
+      // Is that really a big problem?
+      $this->_encounterMedium = CRM_Core_DAO::getFieldValue('CRM_Activity_DAO_Activity', $this->_activityId, 'medium_id');
       if (!array_key_exists($this->_encounterMedium, $encounterMediums)) {
-        $encounterMediums[$this->_encounterMedium] = CRM_Core_OptionGroup::getLabel('encounter_medium',
-          $this->_encounterMedium,
-          FALSE
-        );
+        $encounterMediums[$this->_encounterMedium] = CRM_Core_OptionGroup::getLabel('encounter_medium', $this->_encounterMedium, FALSE);
       }
     }
 
@@ -404,8 +401,6 @@ public function postProcess($params = NULL) {
       $params['parent_id'] = $parentId;
     }
 
-    // store the dates with proper format
-    $params['activity_date_time'] = CRM_Utils_Date::processDate($params['activity_date_time'], $params['activity_date_time_time']);
     $params['activity_type_id'] = $this->_activityTypeId;
 
     // format with contact (target contact) values
diff --git a/CRM/Case/Form/Activity/ChangeCaseStartDate.php b/CRM/Case/Form/Activity/ChangeCaseStartDate.php
index 0494ca135d6b..7066aa10b578 100644
--- a/CRM/Case/Form/Activity/ChangeCaseStartDate.php
+++ b/CRM/Case/Form/Activity/ChangeCaseStartDate.php
@@ -67,7 +67,7 @@ public static function setDefaultValues(&$form) {
     $openCaseParams = array('activity_type_id' => $openCaseActivityType);
     $openCaseInfo = CRM_Case_BAO_Case::getCaseActivityDates($caseId, $openCaseParams, TRUE);
     if (empty($openCaseInfo)) {
-      list($defaults['start_date'], $defaults['start_date_time']) = CRM_Utils_Date::setDateDefaults();
+      $defaults['start_date'] = date('Y-m-d H:i:s');
     }
     else {
       // We know there can only be one result
@@ -76,7 +76,7 @@ public static function setDefaultValues(&$form) {
       // store activity id for updating it later
       $form->openCaseActivityId = $openCaseInfo['id'];
 
-      list($defaults['start_date'], $defaults['start_date_time']) = CRM_Utils_Date::setDateDefaults($openCaseInfo['activity_date'], 'activityDateTime');
+      $defaults['start_date'] = $openCaseInfo['activity_date'];
     }
     return $defaults;
   }
@@ -91,7 +91,7 @@ public static function buildQuickForm(&$form) {
 
     $currentStartDate = CRM_Core_DAO::getFieldValue('CRM_Case_DAO_Case', $caseId, 'start_date');
     $form->assign('current_start_date', $currentStartDate);
-    $form->addDate('start_date', ts('New Start Date'), FALSE, array('formatType' => 'activityDateTime'));
+    $form->add('datepicker', 'start_date', ts('New Start Date'), [], TRUE);
   }
 
   /**
@@ -132,10 +132,6 @@ public static function beginPostProcess(&$form, &$params) {
    * @param $activity
    */
   public static function endPostProcess(&$form, &$params, $activity) {
-    if (!empty($params['start_date'])) {
-      $params['start_date'] = CRM_Utils_Date::processDate($params['start_date'], $params['start_date_time']);
-    }
-
     $caseType = CRM_Utils_Array::first($form->_caseType);
     $caseId = CRM_Utils_Array::first($form->_caseId);
 
@@ -162,7 +158,7 @@ public static function endPostProcess(&$form, &$params, $activity) {
     $currentStartDate = CRM_Utils_Date::customFormat(CRM_Core_DAO::getFieldValue('CRM_Case_DAO_Case',
       $caseId, 'start_date'
     ), $config->dateformatFull);
-    $newStartDate = CRM_Utils_Date::customFormat(CRM_Utils_Date::mysqlToIso($params['start_date']), $config->dateformatFull);
+    $newStartDate = CRM_Utils_Date::customFormat($params['start_date'], $config->dateformatFull);
     $subject = 'Change Case Start Date from ' . $currentStartDate . ' to ' . $newStartDate;
     $activity->subject = $subject;
     $activity->save();
diff --git a/CRM/Case/Form/Activity/OpenCase.php b/CRM/Case/Form/Activity/OpenCase.php
index 55e475134a65..73f6f5a4c45a 100644
--- a/CRM/Case/Form/Activity/OpenCase.php
+++ b/CRM/Case/Form/Activity/OpenCase.php
@@ -98,7 +98,7 @@ public static function setDefaultValues(&$form) {
       return $defaults;
     }
 
-    list($defaults['start_date'], $defaults['start_date_time']) = CRM_Utils_Date::setDateDefaults(NULL, 'activityDateTime');
+    $defaults['start_date'] = date('Y-m-d H:i:s');
 
     // set default case status, case type, encounter medium, location type and phone type defaults are set in DB
     if ($form->_caseStatusId) {
@@ -175,7 +175,7 @@ public static function buildQuickForm(&$form) {
       $csElement->freeze();
     }
 
-    $form->add('text', 'duration', ts('Activity Duration'), array('size' => 4, 'maxlength' => 8));
+    $form->add('number', 'duration', ts('Activity Duration'), ['class' => 'four', 'min' => 1]);
     $form->addRule('duration', ts('Please enter the duration as number of minutes (integers only).'), 'positiveInteger');
 
     if ($form->_currentlyViewedContactId) {
@@ -183,7 +183,7 @@ public static function buildQuickForm(&$form) {
       $form->assign('clientName', $displayName);
     }
 
-    $form->addDate('start_date', ts('Case Start Date'), TRUE, array('formatType' => 'activityDateTime'));
+    $form->add('datepicker', 'start_date', ts('Case Start Date'), [], TRUE);
 
     $form->addField('medium_id', array('entity' => 'activity', 'context' => 'create'), TRUE);
 
@@ -227,9 +227,6 @@ public static function beginPostProcess(&$form, &$params) {
       $form->_currentlyViewedContactId = $params['client_id'][0];
     }
 
-    // for open case start date should be set to current date
-    $params['start_date'] = CRM_Utils_Date::processDate($params['start_date'], $params['start_date_time']);
-
     // rename activity_location param to the correct column name for activity DAO
     $params['location'] = CRM_Utils_Array::value('activity_location', $params);
 
diff --git a/templates/CRM/Activity/Form/Activity.tpl b/templates/CRM/Activity/Form/Activity.tpl
index 6973e09378af..ebf945ceaff9 100644
--- a/templates/CRM/Activity/Form/Activity.tpl
+++ b/templates/CRM/Activity/Form/Activity.tpl
@@ -135,7 +135,7 @@
   <tr class="crm-activity-form-block-activity_date_time">
     <td class="label">{$form.activity_date_time.label}</td>
     {if $action neq 4}
-      <td class="view-value">{include file="CRM/common/jcalendar.tpl" elementName=activity_date_time}</td>
+      <td class="view-value">{$form.activity_date_time.html}</td>
       {else}
       <td class="view-value">{$form.activity_date_time.value|crmDate}</td>
     {/if}
diff --git a/templates/CRM/Case/Form/Activity.tpl b/templates/CRM/Case/Form/Activity.tpl
index fd0a29c33d7e..aa8d78cb5c69 100644
--- a/templates/CRM/Case/Form/Activity.tpl
+++ b/templates/CRM/Case/Form/Activity.tpl
@@ -145,15 +145,12 @@
               </tr>
               <tr class="crm-case-activity-form-block-activity_date_time">
                 <td class="label">{$form.activity_date_time.label}</td>
-                {if $action eq 2 && $activityTypeFile eq 'OpenCase'}
-                  <td class="view-value">{$current_activity_date_time|crmDate}
-                    <div class="description">Use a <a href="{$changeStartURL}">Change Start Date</a> activity to change the date</div>
-                    {* avoid errors about missing field *}
-                    <div style="display: none;">{include file="CRM/common/jcalendar.tpl" elementName=activity_date_time}</div>
-                  </td>
-                {else}
-                  <td class="view-value">{include file="CRM/common/jcalendar.tpl" elementName=activity_date_time}</td>
-                {/if}
+                <td class="view-value">
+                  {$form.activity_date_time.html}
+                  {if $action eq 2 && $activityTypeFile eq 'OpenCase'}
+                    <div class="description">Use a <a class="open-inline" href="{$changeStartURL}">Change Start Date</a> activity to change the date</div>
+                  {/if}
+                </td>
               </tr>
               {if $action eq 2 && $activityTypeFile eq 'OpenCase'}
               <tr class="crm-case-activity-form-block-details">
diff --git a/templates/CRM/Case/Form/Activity/ChangeCaseStartDate.tpl b/templates/CRM/Case/Form/Activity/ChangeCaseStartDate.tpl
index a70ba927452a..8d8c464c6ff6 100644
--- a/templates/CRM/Case/Form/Activity/ChangeCaseStartDate.tpl
+++ b/templates/CRM/Case/Form/Activity/ChangeCaseStartDate.tpl
@@ -35,6 +35,6 @@
     </tr>
     <tr class="crm-case-changecasestartdate-form-block-start_date">
         <td class="label">{$form.start_date.label}</td>
-  <td>{include file="CRM/common/jcalendar.tpl" elementName=start_date}</td>
+        <td>{$form.start_date.html}</td>
     </tr>
    </div>
diff --git a/templates/CRM/Case/Form/Activity/OpenCase.tpl b/templates/CRM/Case/Form/Activity/OpenCase.tpl
index 0117df24753d..569375946925 100644
--- a/templates/CRM/Case/Form/Activity/OpenCase.tpl
+++ b/templates/CRM/Case/Form/Activity/OpenCase.tpl
@@ -34,9 +34,7 @@
   </tr>
   <tr class="crm-case-opencase-form-block-start_date">
     <td class="label">{$form.start_date.label}</td>
-    <td>
-    {include file="CRM/common/jcalendar.tpl" elementName=start_date}
-    </td>
+    <td>{$form.start_date.html}</td>
   </tr>
 
 {* Add fields for attachments *}