(PHP 5 >= 5.1.0, PHP 7) Sets the default timezone used by all date/time functions in a script

(PHP 5 >= 5.3.0, PHP 7) Returns the warnings and errors

(PHP 5 >= 5.2.0, PHP 7) Return time zone relative to given DateTime

(PHP 4, PHP 5, PHP 7) Validate a Gregorian date

(PHP 5 >= 5.3.0, PHP 7) Gets the version of the timezonedb

(PHP 5 >= 5.5.0, PHP 7) Returns the warnings and errors

(PHP 5 >= 5.2.0, PHP 7) Creates new DateTimeZone object

(PHP 5 >= 5.3.0, PHP 7) Creates a new DateInterval object

(PHP 4, PHP 5, PHP 7) Format a GMT/UTC time/date according to locale settings