When trying to make a new DateTime object using PHP, or use any built-in time-related functions, I keep getting the following exception thrown: "DateTime::__construct(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/New_York' for 'EST/-5.0/no DST' instead"
This error means that a PHP script should have some method of having its default timezone set besides the unsafe method of using the system's setting (making for more predictable and consistent behaviour of the script).
In the case of PHP, you can either use date_default_timezone_set() somewhere prior to calling any date or time functions. Alternatively, you can edit the /etc/php.ini file to add a valid timezone to the date.timezone parameter (e.g. date.timezone = "America/New_York") so that all scripts will use this timezone unless set otherwise by using date_default_timezone_set().