php current date = 1 stday of the month code example
Example 1: in date function + 1 month and - 1 day in php
echo Date("Y-m-d", strtotime("2013-01-01 +1 Month -1 Day"));
echo Date("Y-m-d", strtotime("2013-01-31 +1 Month -3 Day"));
echo Date("Y-m-d", strtotime("2013-01-31 +2 Month"));
echo Date("Y-m-d", strtotime("2013-01-31 +3 Month -1 Day"));
echo Date("Y-m-d", strtotime("2013-12-31 -1 Month -1 Day"));
echo Date("Y-m-d", strtotime("2013-12-31 -2 Month"));
echo Date("Y-m-d", strtotime("2013-12-31 -3 Month"));
echo Date("Y-m-d", strtotime("2013-12-31 -3 Month -1 Day"));
Example 2: in date function + 1 month and - 1 day in php
<?php
$months = n;
$years = n;
echo date('Y-m-28', mktime(0, 0, 0, date('m')+$months, 1, date('Y') + $years));
?>