It sounds like the automatic Date & Time setting is turned off.
Scroll down and tapPrivacy.
TapLocation Servicesat the top of the list.

It will allow your iPhone to use theSet Automaticallyfunction in yourDate & Timesettings.
When togglingLocation Servicesoff, a pop-up will appear notifying you that it will deactivate the option for all apps.
How Do I Correct the Time on My iPhone?

Fixing the date and time configs on your iPhone is a fairly straightforward process.
Scroll down and tapGeneral.
In the General menu, tapDate & Time.

IfSet Automaticallyis turned off, tap the toggle to turn it on.
IfSet Automaticallyis turned on, toggle it off and on again.
It should cause your iPhone to reset the date and time to match your location.

Tap the date to pull up a calendar menu and snag the correct date.
Tap the time below the calendar menu to set the current time.
Changes will save automatically.

you could tap< Generalto return to the previous menu or kill the controls menu.
Why Is My iPhone Calendar in the Wrong Time Zone?
It’s the same reason the iPhone is showing the incorrect time.

If your iPhone’s date or time controls are wrong, so will your calendar dates and times.
How Do I Correct the Time in My iPhone Calendar?
If those dont solve the problem, you may need to change the calendar.

Scroll down and tapCalendar.
Scroll down and tapDefault Calendar.
TapAdd Account, then tap the kind of account you wish to add from the pop-up menu.

Exit theAccountsmenu and go back to theDefault Calendarmenu.
opt for new user/account as your default.
Go back to theCalendarmenu and tapTime Zone Override.

Tap the toggle to turnTime Zone Overrideon or off.
If on, it will keep your calendar events and times set to your iPhones designated time zone.
FAQ
Tochange the date on your iPhone, openSettingsand tapGeneral>Date & Time.
Toggle off theSet Automaticallyoption, tap the current date, and then set the date manually.
There’s no official way tochange the snooze time on an iPhone.
However, one workaround is to schedule different alarms at your desired snooze interval times.
Next, create a new alarm for your custom “snooze” time.
To check your screen time on an iPhone, you’ll first need to turn on the feature.
Go toSettings>Screen Time.
TapTurn On Screen Time>Continue.
TapThis is My iPhone, and turn onShare Across Devices.
To view your screen time report, go toSettings>Screen Timeand tapSee All Activity.
TapWeekorDayto see those summaries.