- Locate the SharePoint Server Web site on which you want to enable content approval and item scheduling.
- Click Site Actions, click Site Settings, and then click Modify Pages Library Settings.
- Under General Settings, click Versioning Settings.
- Click Yes next to Content Approval, and then click OK.
- Click Manage item scheduling.
- Click to enable the Enable scheduling of items in this list check box, and then click OK.
Once you turned on scheduling, here is how to adjust the page going-live-time:
On your page while in edit mode click Page->Page Settings and Schedule

Then on a next page you will be given an option to change your schedule and on the same page you will find a list of all the compatible page layouts that inherit from the same content type under Page Layout section:

After you assign desired settings - click OK and you`re done.