get unix timestamp using php

Suppose i know that today's day is monday. How do i use mktime() in php to get unix timestamp for last friday and the friday before that??

suppose today's date is 17-01-2011 and its a monday. Then i want the timestamp for 14-01-2011 00:00:00 and 7开发者_如何学运维-01-2011 00:00:00.

check out strtotime http://php.net/manual/en/function.strtotime.php ..solves most of that kinda issues - otherwise you must strap the date yourself

Something like this should do

<?php
    // Check if today is a Monday
    if (date('N') == 1)
    {
        // Create timestamp for today at 00:00:00
        $today = mktime('0', '0', '0', date('n'), date('j'), date('Y'));

        $last_friday = $today - 60*60*24*3;
        $last_last_friday = $today - 60*60*24*10;

        // Convert to a readable format as a check
        echo 'Last Friday\'s timestamp is ' . $last_friday . ' (' . strftime('%d-%m-%Y %H:%M:%S', $last_friday).') <br />';  
        echo 'Last last Friday\'s timestamp is ' . $last_last_friday . ' (' . strftime('%d-%m-%Y %H:%M:%S', $last_last_friday).')';  
    }

A lot more simpler than you thought (or even I for that matter)! Essentially, strtotime("last friday", time()) gets the timestamp of... last friday!

Getting the current timestamp first:

$unixNow = time();
echo date('r', $unixNow) . "<br />";
//Thu, 10 Jan 2013 15:14:19 +0000

Getting last friday:

$unixLastFriday = strtotime("last friday", $unixNow);
echo date('r', $unixLastFriday) . "<br />";
//Fri, 04 Jan 2013 00:00:00 +0000

Getting the friday before that:

$unixFridayBeforeThat = strtotime("last friday", $unixLastFriday);
echo date('r', $unixFridayBeforeThat) . "<br />";
//Fri, 28 Dec 2012 00:00:00 +0000