Getting last month's date in php

It's simple to get last month date

echo date("Y-n-j", strtotime("first day of previous month"));
echo date("Y-n-j", strtotime("last day of previous month"));

at November 3 returns

2014-10-1
2014-10-31

echo strtotime("-1 month");

That will output the timestamp for last month exactly. You don't need to reset anything afterwards. If you want it in an English format after that, you can use date() to format the timestamp, ie:

echo date("Y-m-d H:i:s",strtotime("-1 month"));

$prevmonth = date('M Y', strtotime("last month"));