Having trouble restricting Date and Time restrictions this should help

Stop them changing the Time Zone.

If your child can manage to change the time zone on their device, then they can get around the settings you have put in place for Down Time.

Use the following steps on your child’s iPhone or iPad:

##BEFORE YOU START##

Turn off screen time passcode by going to Settings, screen time, change screen time pass code, turn off or make sure non is set before you start next steps

If screen time has been enabled then you need to disable them to start.

Go to Settings>General>Date & Time > Toggle on ‘Set Automatically’

Now, got back into screen time and enable it.

Then tap “Content & Privacy Restrictions” and toggle it on

Scroll down and tap ‘Location Services’

Go down to ‘System Services’

Make sure that ‘Setting Time Zone’ is toggled off and then tap ‘Back’

At the top of the ‘Location Services’ screen, check ‘Don’t Allow Changes.’

When you scroll down now you will notice that ‘Setting Time Zone’ is greyed out – meaning that changes can’t be made!

##SET UP THE SCREENTIME PASSCODE AGAIN##

Go back to Settings>General>Date & Time and you’ll see that this has been greyed out too.

If this doesn't work sign the child out of their device and log them back in as a child with the blue link button at the login screen.

Hope this helps. The screentime password disable and re-enable at the end fixed this for me. It's all about the order of operations which makes it difficult for anyone not great with technology. This is why I use android. But my mother in law bought ipads for the kiddos :(