循环2个日期并执行每12天，2天，12天，2天等条件

I want to execute a condition during a loop between 2 dates.

This is my code :

 for($i = $periodStartAt; $periodStartAt <= $endAt; $i->modify('+1 day')){

   // when it's 12 days

   // when it's 2 days (after the 12 days)

   // when it's 12 days (after the 2 days)

   // etc.....

   }

Anyone can help with this algorithm ?

Thanks in advance !

You can consider a period to be 14 days long, which could be split in two subperiods - first of 12 days and the second of 2 days.

So each step of your loop could process 14 days:

$periodStartAt = 0;
while(true) {
    $periodStartAt += 12; // first sub-period
    if ($periodStartAt > $endAt) break;
    //do something when first sub-period reached

    $periodStartAt += 2; //second sub-period 
    if ($periodStartAt > $endAt) break;
    //do something when second sub-period reached
}