hi, can not change time and date on my iphone

Normally, you just need to disable Set Automatically, then you can set the time manually. If this is not an option, there may be several reasons.

• The option to turn Set Automatically on or off might not be available with all carriers or in all countries and regions. If the device has a Screen Time passcode or a corporate profile with device restrictions installed, the setting might be dimmed (grayed out)

You can find more information about it here:

If you can't change the time or time zone on your Apple device - Apple Support

kostia88 wrote:

No, at the night in my country we have changed time ( to winter time, minus -1hour). My phone was switched off, and when at the morning I switched on, he showed wrong time and not my location.

Changing your location back should have sorted this although how location changed is difficult to explain.

Now you will never know if it is the exact time until you go back to automatic.

What is wrong with automatic time? Are you pretending to be in a different location?

You are welcome.