Your question doesn’t make a lot of sense. Are you trying to fake your clock somehow or is the phone incorrectly determining your actual location.

From experience, it seems to me it would use the phone cell towers and/or IP address.

When you turn on a brand new phone, it always seems to know where I am before I set it up.

I tried this before, ended up getting a separate phone.

Too easy to mix up the numbers on accident when making outbound calls.

Some messaging apps won’t allow multiple accounts on the same phone. (WhatsApp)

Work life a balance is gone.

I now use dual SIMs when traveling. Works great.