get the date by adding number of days php

echo “
weekStart=”.date(‘d-m-Y’, mktime(1, 0, 0, date(‘m’), date(‘d’)-(date(‘w’)-1), date(‘Y’))) . ‘ 00:00:00′;

echo “
weekEnd=”.date(‘d-m-Y’, mktime(1, 0, 0, date(‘m’), date(‘d’)-(date(‘w’)-7), date(‘Y’))) . ‘ 23:59:59′;

mind here I used -7 for a week