Add Task Scheduler GUI application (#494)

docs/webapp/applications/apps_overview.md

@@ -20,6 +20,7 @@ ClearML provides the following applications:
 * [**Hyperparameter Optimization**](apps_hpo.md) - Find the parameter values that yield the best performing models
 * **Nvidia Clara** - Train models using Nvidia’s Clara framework
 * [**Project Dashboard**](apps_dashboard.md) - High-level project monitoring with Slack alerts
+* [**Task Scheduler**](apps_task_scheduler.md) - Schedule tasks for one-shot and/or periodic execution at specified times (available under ClearML Enterprise Plan)
 
 ## App Pages Layout
 Each application’s page is split into two sections:

docs/webapp/applications/apps_task_scheduler.md

@@ -0,0 +1,49 @@
+---
+title: Task Scheduler
+---
+
+:::important Enterprise Feature
+The Task Scheduler application is available under the ClearML Enterprise plan
+:::
+
+ClearML's Task Scheduler Application lets you schedule tasks for one-shot and/or periodic execution at specified times. 
+The Scheduler is useful for scheduling routine operations, such as backups, generating reports, as well 
+as periodically running pipelines for updating data and models. 
+
+Each scheduling job is configured with existing ClearML tasks and a scheduling specification for each task: the time 
+for execution and recurrence type. The Scheduler app will then launch copies of the specified tasks at their specified 
+times. 
+
+## Scheduler Instance Configuration
+
+* **Scheduled Tasks** 
+  * **Base Task ID** - ID of an existing ClearML task to schedule. This task will be cloned and enqueued for execution at the specified time. 
+  * **Destination Project** - The project where scheduled tasks will be saved.
+  * **Queue** - The [ClearML Queue](../../fundamentals/agents_and_queues.md#what-is-a-queue) to which scheduled tasks are enqueued (make sure an agent is assigned to that queue)
+  * **Recurrence** - Recurrence type, select one of the following options:
+    * **None** - The task will run once at the specified time.
+    * **Daily** - Task will run every day at the times specified in the `Time of the Day` field
+    * **Weekly** - Task will run every week on the specified day, at the times specified in the `Time of the Day` field
+    * **Monthly** - Task will run every month on the specified days, and at the times specified in the `Time of the Day` field
+    * **Time of the Day** - The time(s) (UTC) at which the task should run
+    * **Add item** - Add another task to schedule 
+* **Scheduling Job Name** - Name for the Scheduler instance. This will appear in the instance list
+
+![TaskScheduler wizard](../../img/apps_taskscheduler_wizard.png)
+
+ 
+## Dashboard
+
+Once a Task Scheduler instance is launched, the dashboard displays a summary of the scheduled tasks.
+
+![TaskScheduler dashboard](../../img/apps_taskscheduler_dashboard.png)
+
+The Task Scheduler dashboard shows:
+* Scheduled Tasks - Table of tasks scheduled for execution. The table displays the ID of the task scheduled for execution,
+  the queue where it will be enqueued, and when it is scheduled to be executed. In the image below, the task in the first
+  row is scheduled to be launched on Sunday at 07:20 UTC (`minute=20, hour=7, day=1`). 
+  ![TaskScheduler scheduler tasks](../../img/apps_taskscheduler_scheduled_tasks.png)
+* Executed Tasks - Table of tasks that have been executed. The table displays the `started` time, which is the time
+  the task was enqueued, and its `finished` time, which is the time the task's execution was completed. If it says `None`,
+  under the `finished` column, the task has not yet completed its execution. 
+  ![TaskScheduler executed tasks](../../img/apps_taskscheduler_executed_tasks.png)

sidebars.js

@@ -83,7 +83,8 @@ module.exports = {
                     'webapp/applications/apps_aws_autoscaler',
                     'webapp/applications/apps_gcp_autoscaler',
                     'webapp/applications/apps_hpo',
-                    'webapp/applications/apps_dashboard'
+                    'webapp/applications/apps_dashboard',
+                    'webapp/applications/apps_task_scheduler'
                 ]
 
             },