why are all my contacts and calender events gone?

"why are all my contacts and calender events gone?: I opened my phone in the middle of the day and all my contacts were gone. I waited until the next day to see if it was just a glitch and everything is gone except all my messages with those numbers. [...]It says I can restore the contacts I had from earlier in the month but just brought back messages from 8 years ago, without contact names. I'm not sure what happened or if it can be fixed."

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I. Troubleshooting Lost Contacts:

Some things to try...

A. Enable Contacts in iCloud Settings:

See If “Contacts” is somehow disabled.

• If it is disabled, then enable it.
• If it is enabled, then disable it and then re-enable it.

B. Retrieve Contacts from Other Devices:

Have a Mac?: Enable Contacts in iCloud on both your iPhone and Mac, and then search through using either device. Using a computer may be more user-friendly when searching through Contacts.

C. Also, Try the Following:

• Restore Contacts, Calendars, Bookmarks, and More Using iCloud.com - Apple Support
• If your iCloud Contacts, Calendars, or Reminders won’t Sync - Apple Support
• Archive the Contacts you Store in iCloud - Apple Support

II. Troubleshooting Lock Calendar:

Syncing Google Calendar and iCloud Calendar:

If the were syncing through a third-party (i.e. Google Calendar), then it may be a syncing issue. To sync Google Calendar with iCloud Calendar, you'll need to add your Google account to your Apple device or subscribe to your iCloud calendar within Google Calendar.

Source: syncing google calendar and iCloud calendar

Use these Sites:

• Apple: Add or Delete Calendar Accounts on Mac - Apple Support
• Google: How to Add Another eMail Address to my Google Calendar - gmail Help - Google