AFAIK, There is a differenece in Activate/Deactivate Later date/time of a page and the On/Off Time property of a page.
Activate/Deactivate Later won't activate/deactivate the page until the configured time/date to the Publish instance. As for On/Off Time, requires a separate Activate/Deactivate action, but won't display on the Publish instance until the On Time matches Current Time.
This can come in handy when you have a lot of pages that need to be suddenly displayed at a certain time all at once and you can't afford a big Replication Queue. With On Time you can activate to the Publish instance, yet the page won't display until On Time has reached and be sure that all pages will display at the same time. Similar goes for Off time.
Additionally you can also define an off-time after which the page will no longer be displayed.
There is also one difference between Activate Later and On-Time in situation where you work with pages which are already published.
Here the visibility of pages on the live system is different. If you use Active Later, the live page on the publish instance gets replaced at the specified date/time. But if you use On-Time and activate the page before, the current live page on the publish instance is replaced immediately and will be invisible until the specified On-Time is reached. Similar for off time property.
Hope this helps clarify.
Hi varun ,
Thanks for the reply .
Can you please elaborate on the "activate/de-activate Later" process.
What i am interested to know is "does Cq use a internal scheduler/handler" in its author that keeps checking for this "activate/de-activate later date/time" to trigger the replication process.
If so what is the process/scheduler/handler that moniters this.
Thanks in advance
It leverages workflows and Sling eventing to control the activation. See http://dev.day.com/docs/en/cq/current/wcm/page_publish.html#Scheduling%20a%20Page%20for%20 Activation for information on the CQ UI to start the process. The workflow started is /etc/workflow/models/scheduled_activation.html. The workflow uses the Sling scheduler to set the time for the activation based on the user input (which is stored in the workflow meta-data as the absolute time). See http://sling.apache.org/documentation/the-sling-engine/eventing-and-jobs.html for general information on Sling scheduler and it's internal implementation.