The Mktime() function is an inbuilt function in PHP which is used to return the Unix timestamp for a date. The timestamp returns a long integer containing the number of seconds between the Unix Epoch (January 1, 1970, 00:00:00 GMT) and the time specified.

Syntax:

Int Mktime( $hour, $minute, $second, $month, $day, $year, $is_dst)

parameters

This function has seven optional parameters as mentioned below:

$hour: It is a parameter which specifies the hour.
$minute: It is a parameter which specifies the minute.
$second: It is a parameter which specifies the second.
$month: It is a parameter which specifies the month.
$day: It is a parameter which specifies the day.
$year: It is a parameter which specifies the year.
$is_dst: It is a parameter which can be set to 1 if the time is during daylight savings time (DST), or 0 if it is not.

<?php

// Using mktime() function to know the day
echo "May 21,2022 was on a " . date("l",
mktime(3, 12, 15, 5, 21, 2022));
?>

Output
May 1, 2022 was on a saturday

<?php

// Using mktime() function to know the complete date
echo date("M-d-Y", mktime(0, 0, 0, 5, 21, 2022)) . "<br>";

// Using mktime() function to know the
// complete date for an out-of-range input
echo date("M-d-Y", mktime(0, 0, 0, 6, 21, 2022));

?>

Output

May-05-2022
May-06-2022