Get date range by this week, last week, this month, and last month options by providing offsets.

<?php
function getWeekRange(&$start_date, &$end_date, $offset=0) {
        $start_date = '';
        $end_date = '';   
        $week = date('W');
        $week = $week - $offset;
        $date = date('Y-m-d');
       
        $i = 0;
        while(date('W', strtotime("-$i day")) >= $week) {                       
            $start_date = date('Y-m-d', strtotime("-$i day"));
            $i++;       
        }   
           
        list($yr, $mo, $da) = explode('-', $start_date);   
        $end_date = date('Y-m-d', mktime(0, 0, 0, $mo, $da + 6, $yr));
}
   
    function getMonthRange(&$start_date, &$end_date, $offset=0) {
        $start_date = '';
        $end_date = '';   
        $date = date('Y-m-d');
       
        list($yr, $mo, $da) = explode('-', $date);
        $start_date = date('Y-m-d', mktime(0, 0, 0, $mo - $offset, 1, $yr));
       
        $i = 2;
       
        list($yr, $mo, $da) = explode('-', $start_date);
       
        while(date('d', mktime(0, 0, 0, $mo, $i, $yr)) > 1) {
            $end_date = date('Y-m-d', mktime(0, 0, 0, $mo, $i, $yr));
            $i++;
        }
}

getWeekRange($start, $end);
echo "$start $end";

getMonthRange($start, $end);
echo "$start $end";

?>