从给定日期获取一周前 PHP

Question

I have a monthly bill table that stored where customer need to pay the bill in Ymd format, i need to send an email notification a week before this due date. for example:

public function cronSendNotif($transaction){
  $dueDate = $transaction->getDueDate(); // 2019-08-03
  $weekAgo = $this->getWeekAgoDate($dueDate); // 2019-07-27

  $this->sendEmailNotification($transaction->getId(),$weekAgo);
}

private function getWeekAgoDate($dueDate){
   // how ??
}

how can i get the week ago date in Ymd format , if i have this given date in Ymd format?

Answer 1

Try this:

private function getWeekAgoDate($dueDate){
  $weekAgo = date('Y-m-d', strtotime('-7 days', strtotime($dueDate)));
  return $weekAgo;
}

Answer 2

Using strtotime, you can simply add/subtract days, weeks etc. from a date. Example:

function getWeekAgoDate($dueDate){
   return date("Y-m-d", strtotime($dueDate . "-1 week"));
}

Answer 3

You can also make use of the modify function.

$weekAgo = getWeekAgoDate($dueDate);
echo $weekAgo->format('Y-m-d H:i:s');

function getWeekAgoDate(DateTime $dueDate){
   return $dueDate->modify("- 7 days");
}

Documentation: php.net/manual/en/datetime.modify.php