How to get timezone based on phone country code in php

In my project : User is register by phone number and phone country code. Once they will register then I want to store that user time zone in database.

For example : User is register using this
phone number 78548956..
phone country code +91

then I want to store user time zone (UTC +5:30) in database.

IS there any api or script or function for fetch time zone using country code (+91 etc ..)?

I have directly created new table using country code and time zone for it. and once user will register in system then I am checking country code in that new table and fetching time zone according to match in db. But I don’t want to create new table. if there have any other way then please suggest me.