Verify what your host has said as a first step. Not saying they are wrong but its worth the minute to check yourself first.
View phpinfo to see what it is set at for real. This is what mine looks like:
View attachment 184510
That is correct for the location, well it is an hour out (given that it is now Autumn/Fall here) but it is 'near enough' , if that makes sense...
Assume you are asking AZ = Arizona and not somewhere in Australia yes ? In any case either would be different to the above afaik...