iPhone 12 Pro Max is showing incorrect date

"iPhone 12 Pro Max is showing incorrect date: I have a problem in my date in this iphone 12 pro max"

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Incorrect Date on iPhone:

Set it to how it should be. Go here: Change the date and time on iPhone - Apple Support

Is this in the Calendar app?

What kind of problem? What it is showing instead of what it should be? Is the device connected to the internet, cellular?