Finding next 13 Mondays and the last Monday

Question

I have the following code that return's the next 13 Mondays from today's date.

for($i=1; $i<=13; $i++){
    echo date("Y-m-d", strtotime('+'.$i.' Monday'))."<br>";
}

I want to be able to amend this so it not only shows the next 13 Mondays but the Monday that has just past.

I tried amending the code as follows but I then get two instances of the next Monday returned.

for($i=-1; $i<=13; $i++){
echo date("Y-m-d", strtotime('+'.$i.' Monday'))."<br>";
}

Data returned.

2015-04-13
2015-04-20  //<--
2015-04-20
2015-04-27
2015-05-04
2015-05-11
2015-05-18
2015-05-25
2015-06-01
2015-06-08
2015-06-15
2015-06-22
2015-06-29
2015-07-06
2015-07-13

Any ideas on how I achieve this?

Answer 1

I would do it like this:

for($i =- 1; $i <= 13; $i == 0 ? $i += 2 : $i++){
    echo date("Y-m-d", strtotime("$i Monday")) . "<br>";
}

Using a ternary operator to check if $i is 0 - and if, increase it by 2 instead of 1 :)

Answer 2

Try this:

echo date("Y-m-d", strtotime('-1 Monday'))."<br>";
for($i=1; $i<=13; $i++){
    echo date("Y-m-d", strtotime('+'.$i.' Monday'))."<br>";
}

Or you need only one for statement?

Answer 3

function mondays() {
    $begin = new DateTime('last monday');
    $end = clone $begin;
    $end->add(new DateInterval('P14W')); // next 13 + last

    $interval = new DateInterval('P1W');
    $daterange = new DatePeriod($begin, $interval ,$end);

    foreach($daterange as $date){
        yield $date;
    }
}


foreach(mondays() as $date){
    echo $date->format("Y-m-d"), PHP_EOL;
}