PHP mktime() Function

Return the Unix timestamp for a date. Then use it to find the day of that date:

<?php
// Prints: October 3, 1975 was on a Friday
echo "Oct 3, 1975 was on a ".date("l", mktime(0,0,0,10,3,1975));
?>

Definition and Usage

The mktime() function returns the Unix timestamp for a date.

Tip: This function is identical to gmmktime() except the passed parameters represents a date (not a GMT date).

mktime(hour, minute, second, month, day, year, is_dst)

Parameter	Description
hour	Optional. Specifies the hour
minute	Optional. Specifies the minute
second	Optional. Specifies the second
month	Optional. Specifies the month
day	Optional. Specifies the day
year	Optional. Specifies the year
is_dst	Optional. Set this parameter to 1 if the time is during daylight savings time (DST), 0 if it is not, or -1 (the default) if it is unknown. If it's unknown, PHP tries to find out itself (which may cause unexpected results). Note: This parameter is removed in PHP 7.0. The new timezone handling features should be used instead

Return Value:	Returns an integer Unix timestamp. FALSE on error
PHP Version:	4+
PHP Changelog:	PHP 7.1: The is_dst parameter is removed. PHP 5.3.0: Throws E_DEPRECATED if the is_dst parameter is used PHP 5.1: The is_dst parameter was deprecated. If mktime() is called with no arguments, it now throws E_STRICT notice. Use the time() function instead.