calendars and contacts do not appear in my icloud backup list?

That is correct. From the article linked to above under "Related Article":

Your iPhone, iPad, and iPod touch backups only include information and settings stored on your device. They do not include information already stored in iCloud such as Contacts, Calendars, Bookmarks, Notes, Reminders, Voice Memos4, Messages in iCloud, iCloud Photos, and shared photos. Some information is not included in an iCloud backup but can be added to iCloud and shared across multiple devices like Mail, Health data, call history, and files you store in iCloud Drive.

As noted, Contacts and Calendar are NOT part of the backup. It doesn't matter how often you back up your device, those things won't get backed up.

It sounds as if you may be confusing backing up with syncing. If that's the case, you're looking in the wrong place. Go to Settings>Apple ID>iCloud>Apps Using iCloud>Show All. From there you should be able to turn on Contacts and Calendar.

See also:

If your iCloud Contacts, Calendars, or Reminders won’t sync - Apple Support