diff --git a/module/project/ui/common.field.php b/module/project/ui/common.field.php
index 70ae158ba8..9d8b93d8b3 100644
--- a/module/project/ui/common.field.php
+++ b/module/project/ui/common.field.php
@@ -44,20 +44,22 @@ if($hasCode)
 
 $fields->field('PM')->control('picker')->items(data('PMUsers'));
 
+$isLongTime = data('copyProject') ? data('copyProject.end') == LONG_TIME : data('project.end') == LONG_TIME;
 $fields->field('begin')
     ->label($lang->project->planDate)
+    ->checkbox(array('text' => $lang->project->longTime, 'name' => 'longTime', 'checked' => $isLongTime))
     ->required()
     ->control('inputGroup')
     ->itemBegin('begin')->control('datePicker')->placeholder($lang->project->begin)->value(data('project.begin') ? data('project.begin') : date('Y-m-d'))->required(true)->itemEnd()
     ->item(array('control' => 'span', 'text' => '-'))
-    ->itemBegin('end')->control('datePicker')->placeholder($lang->project->end)->required(true)->value(data('project.end'))
+    ->itemBegin('end')->control('datePicker')->placeholder($lang->project->end)->required(true)->value(data('project.end'))->className('end-picker')->disabled($isLongTime)
     ->menu(array('items' => jsRaw('window.getDateMenu')))
     ->itemEnd()
     ->tip(' ')
     ->tipProps(array('id' => 'dateTip'))
     ->tipClass('text-warning hidden');
 
-$fields->field('days')->label($lang->project->days . $lang->project->daysUnit)->control('input');
+$fields->field('days')->label($lang->project->days . $lang->project->daysUnit)->control('input')->hidden($isLongTime);
 
 $fields->field('productsBox')
     ->width('full')
diff --git a/module/project/ui/create.html.php b/module/project/ui/create.html.php
index 3b37a1e3b5..2864459772 100644
--- a/module/project/ui/create.html.php
+++ b/module/project/ui/create.html.php
@@ -65,6 +65,7 @@ formGridPanel
     on::click('[name=name], [name=code], [name=end], [name=days], [data-name="parent"] .pick *', 'removeTips'),
     on::click('[type=submit]', 'removeAllTips'),
     on::change('[name=hasProduct]', 'changeType'),
+    on::change('[name=longTime]')->do('$("[name=end]").zui("datePicker").render({disabled: $(target).prop("checked")}); $("[data-name=days]").toggleClass("hidden",$(target).prop("checked"));'),
     on::change('[name=future]', 'toggleBudget'),
     on::change('[name=begin], [name=end]', 'computeWorkDays'),
     on::change('[name^=products]', 'toggleStageBy'),
diff --git a/module/project/ui/edit.html.php b/module/project/ui/edit.html.php
index 2083a79a9e..c972be9c5a 100644
--- a/module/project/ui/edit.html.php
+++ b/module/project/ui/edit.html.php
@@ -59,6 +59,7 @@ formGridPanel
             )
     ),
     on::change('[name=hasProduct]', 'changeType'),
+    on::change('[name=longTime]')->do('$("[name=end]").zui("datePicker").render({disabled: $(target).prop("checked")}); $("[data-name=days]").toggleClass("hidden",$(target).prop("checked"));'),
     on::change('[name=future]', 'toggleBudget'),
     on::change('[name=begin], [name=end]', 'computeWorkDays'),
     on::change('[name=parent], [name=budget]', 'checkBudget'),
diff --git a/module/project/zen.php b/module/project/zen.php
index 91452a13c9..a2da1cd986 100755
--- a/module/project/zen.php
+++ b/module/project/zen.php
@@ -20,8 +20,8 @@ class projectZen extends project
     protected function prepareCreateExtras(object $postData): object|false
     {
         $project = $postData->setDefault('status', 'wait')
-            ->setIF($this->post->delta    == 999, 'end', LONG_TIME)
-            ->setIF($this->post->delta    == 999, 'days', 0)
+            ->setIF($this->post->longTime, 'end', LONG_TIME)
+            ->setIF($this->post->longTime, 'days', 0)
             ->setIF($this->post->acl      == 'open', 'whitelist', '')
             ->setIF(!isset($_POST['whitelist']), 'whitelist', '')
             ->setIF($this->post->multiple != 'on', 'multiple', '0')
@@ -83,8 +83,8 @@ class projectZen extends project
             ->setDefault('lastEditedBy', $this->app->user->account)
             ->setDefault('lastEditedDate', helper::now())
             ->setDefault('days', '0')
-            ->setIF($this->post->delta == 999, 'end', LONG_TIME)
-            ->setIF($this->post->delta == 999, 'days', 0)
+            ->setIF($this->post->longTime, 'end', LONG_TIME)
+            ->setIF($this->post->longTime, 'days', 0)
             ->setIF($this->post->future, 'budget', 0)
             ->setIF($this->post->budget != 0, 'budget', round((float)$this->post->budget, 2))
             ->join('whitelist', ',')