You must have seen how to get today date by using date function. By changing the date value we can get the dates of yesterday. Same way we can extend this to get date values of last 7 days. Or we can extend this to get dates between any to differences.
Let us find out the date value of yesterday.
$m= date("m"); // Month value
$de= date("d"); //today's date
$y= date("Y"); // Year value
echo date('d-m-y:D', mktime(0,0,0,$m,($de-1),$y));
Last seven days date value we can find out by using a for loop.
Here is the output of the code.