Hi s_scheid,
If you haven't done so yet, restart your iPhone. Although simple, this step can help correct some unexpected issues. It's also a good idea to make sure your iPhone is running the latest iOS version, since this can help with overall performance: Apple security updates. If an update is available, be sure to create a backup before installing it.
If the date and time still shows incorrect information, set the date and time manually as mentioned here: If you can't change the time or time zone on your Apple device.
Set the date and time manually
If your device still shows an incorrect date, time, or time zone, change each setting manually instead of using Set Automatically. For example, you might have iOS 9 or earlier, and your country or region, or government changes the time zone or the observance of daylight saving time.
On your iPhone or iPad
1. Go to Settings > General > Date & Time.
2. Turn off Set Automatically. Is this setting dimmed?
3. Change the time zone or the date and time:
• Tap Time Zone and enter a city with the time zone that you need.
• Or tap the date to change the date and time.
Cheers.