Go to Shared Documents=> Library Settings => General Settings => Manage Item Scheduling.
Programmatically enable scheduling of items in the list:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.SharePoint;
using Microsoft.Office.DocumentManagement.MetadataNavigation;
using System.Reflection;
namespace EnableItemScheduling
{
class Program
{
static void Main(string[] args)
{
using (SPSite site = new SPSite("http://serverName:1111/"))
{
using (SPWeb web = site.RootWeb)
{
SPList list = web.Lists.TryGetList("Shared Documents");
list.EnableModeration = true;
list.EnableMinorVersions = true;
list.Update();
typeof(Microsoft.SharePoint.Publishing.ScheduledItem).GetMethod("RegisterSchedulingEventOnList", BindingFlags.Static | BindingFlags.NonPublic).Invoke(null, new object[] { list });
}
}
}
}
}