add time based task execution

website/content/docs/release-notes/nomad/v1_8_x.mdx

@@ -58,6 +58,11 @@ We are pleased to announce the following Nomad updates.
   garbage-collected. Now, the jobs list will update in real-time as jobs are
   created, updated, or removed. Further, any changes to allocations of jobs
   on-page will be reflected in the status of that job in real-time.
+
+- **Time based task execution:** Using a CRON-like syntax, operators can now
+  schedule when tasks should execute and when they should stop. This provides
+  governance for tasks executed from jobs, and allows operators to easily opt-in 
+  or opt-out of a schedule that governs when the task can run through the web based UI.
 
 - **Sentinel policy management in the Web UI:** Enterprise users can manage
   Sentinel policies directly within the Nomad UI. Users can create a Sentinel