PHP mktime() Function – Getting a Unix Timestamp

This page shares a PHP knowledge point: the mktime() function returns a Unix timestamp for a given date and time.

Syntax :

int mktime([int $hour = date("H")], [int $minute = date("i")], [int $second = date("s")], [int $month = date("n")], [int $day = date("j")], [int $year = date("Y")], [int $is_dst = -1])

The function calculates the number of seconds elapsed since the Unix epoch (January 1 1970 00:00:00 GMT). Parameters may be omitted from right to left; omitted values default to the current local date and time.

Parameters :

hour – hour of the day.

minute – minute of the hour.

second – seconds (0‑59).

month – month number.

day – day of the month.

year – two‑ or four‑digit year (0‑69 maps to 2000‑2069, 70‑100 maps to 1970‑2000).

is_dst – 1 if daylight‑saving time is in effect, 0 if not, or -1 (default) if unknown; PHP will try to determine it.

Return value : the Unix timestamp corresponding to the supplied arguments.

Example :

<?php
// Set the default timezone (available since PHP 5.1)
date_default_timezone_set('UTC');

// Prints: July 1, 2000 is on a Saturday
echo "July 1, 2000 is on a " . date('l', mktime(0, 0, 0, 7, 1, 2000)) . "
";

// Prints something like: 2006-04-05T01:02:03+00:00
echo date('c', mktime(1, 2, 3, 4, 5, 2006));
?>

The article ends with a reminder that following and sharing knowledge is a virtue.