php function for get all mondays within date range

Question

Example: $startDate is Monday 2007-02-05 and $endDate is Tuesday 2007-02-20. Then I want it to list:

Monday 2007-02-05
Monday 2007-02-12
Monday 2007-02-19

I looked at the PHP manual and found this to get all the days between two dates. But how to do it the way i want? PHP Code:

Answer 1

Rather than get all days and loop through them all, get the first Monday after the start date and then iterate 7 days at a time:

$endDate = strtotime($endDate);
for($i = strtotime('Monday', strtotime($startDate)); $i <= $endDate; $i = strtotime('+1 week', $i))
    echo date('l Y-m-d', $i);

Answer 2

I needed the same and created a simple method.

public function getMondaysInRange($dateFromString, $dateToString)
{
    $dateFrom = new \DateTime($dateFromString);
    $dateTo = new \DateTime($dateToString);
    $dates = [];

    if ($dateFrom > $dateTo) {
        return $dates;
    }

    if (1 != $dateFrom->format('N')) {
        $dateFrom->modify('next monday');
    }

    while ($dateFrom <= $dateTo) {
        $dates[] = $dateFrom->format('Y-m-d');
        $dateFrom->modify('+1 week');
    }

    return $dates;
}

Then use it.

$dateFromString = '2007-02-05';
$dateToString = '2007-02-20';
var_dump($this->getMondaysInRange($dateFromString, $dateToString));

Result:

array (size=3)
  0 => string '2007-02-05' (length=10)
  1 => string '2007-02-12' (length=10)
  2 => string '2007-02-19' (length=10)

Maybe it will be helpful for somebody.