There are so many places where you can modify the time settings in a set up of Linux, Apache, PHP, and MySQL. I need to set everything to UTC in my server and I wondered why not just set the system time to UTC and all services just need to use the timezone "SYSTEM" as I did for MySQL.
However, a simple PHP warning made me doubt my decision. "It is not safe to reply on the system's timezone settings"
I have to questions, one may lead to another.
- Why is it not safe to rely on the system time settings, specifically CentOS, in PHP, Apache, or MySQL?
- What is the best way to unify the time settings from all services: Apache, PHP, and MySQL?