(PHP 4, PHP 5, PHP 7) Get Unix timestamp for midnight on Easter of a given year

(PECL hrtime >= 0.4.3) Get elapsed ticks for all intervals.

(PHP 5 >= 5.6.0, PHP 7) Returns new DateTimeImmutable object encapsulating the given DateTime object

(PHP 4, PHP 5, PHP 7) Converts a date from the French Republican Calendar to a Julian Day Count

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

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

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

(PHP 5 >= 5.3.0, PHP 7) Alias of

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

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