I have a 3rd generation iPod (Apple calls it an "iPod (Dock Connector)"). It syncs music, podcasts and audiobooks with iTunes 12.5.3 on El Capitan, but calendars and contacts are not synced. (I didn't notice this previously, because until recently I didn't use Apples calendar/contact apps). iPod has most recent firmware (Settings > About reports version 2.3).
How can I get calendar events and contacts to sync with this vintage iPod?